Cisco Applied Mitigation Bulletin-
Microsoft announced eight security bulletins that address 23 vulnerabilities as part of the monthly security bulletin release on August 13, 2013. A summary of these bulletins is on the Microsoft website at http://technet.microsoft.com/en-us/security/bulletin/ms13-aug. This document provides identification and mitigation techniques that administrators can deploy on Cisco network devices.
The vulnerabilities that have a client software attack vector, can be exploited locally on the vulnerable device, require user interaction, or can be exploited using web-based attacks (these include but are not limited to cross-site scripting, phishing, and web-based email threats) and email attachments are in the following list:
The vulnerabilities that have a network mitigation are in the following list. Cisco devices provide several countermeasures for the vulnerabilities that have a network attack vector, which will be discussed in detail later in this document.
Information about affected and unaffected products is available in the respective Microsoft advisories and the Cisco Alerts that are referenced in Cisco Event Response: Microsoft Security Bulletin Release for August 2013.
In addition, multiple Cisco products use Microsoft operating systems as their base operating system. Cisco products that may be affected by the vulnerabilities described in the referenced Microsoft advisories are detailed in the "Associated Products" table in the "Product Sets" section.
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MS13-059, Cumulative Security Update for Internet Explorer (2862772): These vulnerabilities have been assigned Common Vulnerabilities and Exposures (CVE) identifiers CVE-2013-3184, CVE-2013-3186, CVE-2013-3187, CVE-2013-3188, CVE-2013-3189, CVE-2013-3190, CVE-2013-3191, CVE-2013-3192, CVE-2013-3193, CVE-2013-3194, and CVE-2013-3199. These vulnerabilities can be exploited remotely without authentication and without user interaction. The attack vector for exploitation of these vulnerabilities is through HTTP packets, which typically use TCP port 80 but may also use TCP ports 3128, 8000, 8010, 8080, 8888, and 24326.
Successful exploitation of the vulnerabilities that are associated with CVE-2013-3184, CVE-2013-3187, CVE-2013-3188, CVE-2013-3189, CVE-2013-3190, CVE-2013-3191, CVE-2013-3193, CVE-2013-3194, and CVE-2013-3199 may allow remote code execution. No network mitigations will be presented in this bulletin for these vulnerabilities.
Successful exploitation of the vulnerability that is associated with CVE-2013-3186 may allow elevation of privilege. No network mitigations will be presented in this bulletin for this vulnerability.
Successful exploitation of the vulnerability that is associated with CVE-2013-3192 may allow information disclosure, which enables an attacker to learn information about the affected device. Cross-site scripting and phishing could also be used to exploit this vulnerability. Due to the nature of cross-site scripting vulnerabilities, no additional information will be presented in this bulletin for this vulnerability.
For additional information about cross-site scripting attacks and the methods used to exploit these vulnerabilities, refer to the Cisco Applied Mitigation Bulletin Understanding Cross-Site Scripting (XSS) Threat Vectors.
MS13-060, Vulnerability in Unicode Scripts Processor Could Allow Remote Code Execution (2850869): This vulnerability has been assigned CVE identifier CVE-2013-3181. This vulnerability can be exploited remotely, without authentication, and requires user interaction. Successful exploitation of this vulnerability may allow arbitrary code execution. The attack vector for exploitation is via the rendering of a crafted Embedded OpenType (EOT) font in applications such as Microsoft Internet Explorer, Microsoft Office PowerPoint, or Microsoft Office Word. Potential exploitation of this vulnerability uses web-based threats, and exploitation may be through the use of HTTP packets, which typically use TCP port 80 but may also use TCP ports 3128, 8000, 8010, 8080, 8888, and 24326. This vulnerability can be exploited via web-based threats (these include but are not limited to cross-site scripting, phishing, and web-based email), email attachments, and files stored on network shares.
The Cisco ASA 5500 Series Adaptive Security Appliance, the Cisco Catalyst 6500 Series ASA Services Module (ASASM), the Cisco Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, and the Cisco ACE Application Control Engine Appliance and Module provide protection for potential attempts to exploit this vulnerability (a topic that is included in this document).
MS13-064, Vulnerability in Direct Access Server Could Allow Denial of Service (2849568): This vulnerability has been assigned CVE identifier CVE-2013-3182. This vulnerability can be exploited remotely without authentication and without user interaction. Successful exploitation of this vulnerability may result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition. The attack vector uses ICMPv6 packets. An attacker could exploit this vulnerability using spoofed packets.
The Cisco ASA 5500 Series Adaptive Security Appliance, the Cisco Catalyst 6500 Series ASA Services Module (ASASM), and the Cisco Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers provide protection for potential attempts to exploit this vulnerability (a topic that is included in this document).
MS13-065, Vulnerability in ICMPv6 Could Allow Denial of Service (2868623): This vulnerability has been assigned CVE identifier CVE-2013-3182. This vulnerability can be exploited remotely without authentication and without user interaction. Successful exploitation of this vulnerability may result in a DoS condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition. The attack vector uses ICMPv6 packets. An attacker could exploit this vulnerability using spoofed packets.
The Cisco ASA 5500 Series Adaptive Security Appliance, the Cisco Catalyst 6500 Series ASA Services Module (ASASM), and the Cisco Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers provide protection for potential attempts to exploit this vulnerability (a topic that is included in this document).
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Information about vulnerable, unaffected, and fixed software is available in the Microsoft Security Bulletin Summary for August 2013, which is available at the following link: http://www.microsoft.com/technet/security/bulletin/ms13-aug.mspx
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The vulnerabilities that have a client software attack vector, can be exploited locally on the vulnerable device, require user interaction, or can be exploited using web-based attacks (these include but are not limited to cross-site scripting, phishing, and web-based email threats) and email attachments are in the following list:
These vulnerabilities are mitigated most successfully at the endpoint through software updates, user education, desktop administration best practices, and endpoint protection software such as host intrusion prevention systems (HIPS) or antivirus products.
The vulnerabilities that have a network mitigation are in the following list. Cisco devices provide several countermeasures for these. This section of the document provides an overview of these techniques.
Cisco IOS Software can provide effective means of exploit prevention using the following methods:
- IPv6 Unicast Reverse Path Forwarding (uRPF)
- IPv6 First Hop Security (FHS)
These protection mechanisms filter and drop as well as verify the source IP address of packets that are attempting to exploit the vulnerabilities that have a network attack vector.
The proper deployment and configuration of IPv6 uRPF provides an effective means of protection against attacks that use packets with spoofed source IP addresses. Unicast RPF should be deployed as close to all traffic sources as possible.
The proper deployment and configuration of IPv6 First Hop Security (FHS) provides an effective means of protection against Layer 2 IPv6 attacks that could be used to exploit MS13-064 and MS13-065. No more details about the deployment of FHS will be presented in this document. For more details about FHS, see IPv6 First Hop Security (FHS).
Because the potential exists that a trusted networking client could become affected by malicious code that does not use packets with spoofed source addresses, IPv6 uRPF and FHS do not provide complete protection against these vulnerabilities.
Effective exploit prevention can also be provided by the Cisco ASA 5500 Series Adaptive Security Appliance, Cisco Catalyst 6500 Series ASA Services Module (ASASM), and the Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers using the following methods:
- Layer 3/Layer 4 inspection
- Application layer protocol inspection
Effective exploit prevention can also be provided by the Cisco ACE Application Control Engine Appliance and Module using application protocol inspection.
Cisco IOS Software, Cisco ASA, Cisco ASASM, Cisco FWSM firewalls, and Cisco ACE Application Control Engine Appliance and Module can provide visibility through syslog messages and counter values displayed in the output from show commands.
Effective use of Cisco Intrusion Prevention System (IPS) event actions provides visibility into and protection against attacks that attempt to exploit these vulnerabilities as discussed later in this document.
The Cisco Security Manager can also provide visibility through incidents, queries, and event reporting.
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Organizations are advised to follow their standard risk evaluation and mitigation processes to determine the potential impact of these vulnerabilities. Triage refers to sorting projects and prioritizing efforts that are most likely to be successful. Cisco has provided documents that can help organizations develop a risk-based triage capability for their information security teams. Risk Triage for Security Vulnerability Announcements and Risk Triage and Prototyping can help organizations develop repeatable security evaluation and response processes.
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Caution: The effectiveness of any mitigation technique depends on specific customer situations such as product mix, network topology, traffic behavior, and organizational mission. As with any configuration change, evaluate the impact of this configuration prior to applying the change.
Specific information about mitigation and identification is available for these devices:
- Cisco IOS Routers and Switches
- Cisco ASA, Cisco ASASM, and Cisco FWSM Firewalls
- Cisco ACE
- Cisco Intrusion Prevention System
- Cisco Security Manager
Cisco IOS Routers and Switches
Mitigation: Spoofing Protection
Mitigation: IPv6 Spoofing Protection Using Unicast Reverse Path Forwarding
Some of the vulnerabilities described in this document have attack vectors that can be exploited by spoofed IPv6 packets. The proper deployment and configuration of IPv6 Unicast Reverse Path Forwarding (uRPF) can provide protection mechanisms for spoofing related to the following vulnerabilities:
uRPF is configured at the interface level and can detect and drop packets that lack a verifiable source IP address. Administrators should not rely on uRPF to provide complete spoofing protection because spoofed packets may enter the network through a uRPF-enabled interface if an appropriate return route to the source IP address exists. Administrators are advised to take care to ensure that the appropriate uRPF mode (loose or strict) is configured during the deployment of this feature because it can drop legitimate traffic that is transiting the network. In an enterprise environment, uRPF may be enabled at the Internet edge and the internal access layer on the user-supporting Layer 3 interfaces.
For additional information about the configuration and use of uRPF, reference the Understanding Unicast Reverse Path Forwarding Cisco Security Intelligence Operations white paper.
Identification: Spoofing Protection Using Unicast Reverse Path Forwarding
With uRPF properly deployed and configured throughout the network infrastructure, administrators can use the show cef interface type slot/port internal, show ipv6 interface, show ipv6 cef switching statistics feature, and show ipv6 traffic commands to identify the number of packets that uRPF has dropped.
Note: Beginning with Cisco IOS Software Release 12.4(20)T, the command show ipv6 cef switching has been replaced by show ipv6 cef switching statistics feature.
Note: The show command | begin regex and show command | include regex command modifiers are used in the following examples to minimize the amount of output that administrators will need to parse to view the desired information. Additional information about command modifiers is in the show command sections of the Cisco IOS Configuration Fundamentals Command Reference.
router#show cef interface GigabitEthernet 0/0 internal | include drop ip verify: via=rx (allow default), acl=0, drop=18, sdrop=0 IPv6 unicast RPF: via=rx acl=None, drop=10, sdrop=0 router#
Note: show cef interface type slot/port internal is a hidden command that must be fully entered at the command-line interface. Command completion is not available for it.
router#show ipv6 interface GigabitEthernet 0/0 | section IPv6 verify IPv6 verify source reachable-via rx 0 verification drop(s) (process), 10 (CEF) 0 suppressed verification drop(s) (process), 0 (CEF) -- CLI Output Truncated -- router# router#show ipv6 cef switching statistics feature IPv6 CEF input features: Feature Drop Consume Punt Punt2Host Gave route RP LES Verify Unicast R 10 0 0 0 0 Total 10 0 0 0 0 -- CLI Output Truncated -- router# router#show ipv6 traffic | include RPF 10 RPF drops, 0 RPF suppressed, 0 forced drop router#
In the preceding show cef interface type slot/port internal, show ipv6 interface type slot/port, show ipv6 cef switching statistics feature, and show ipv6 traffic examples, uRPF has dropped 10 IPv6 packets received globally on all interfaces with IPv6 uRPF configured because of the inability to verify the source address of the IP packets within the forwarding information base of Cisco Express Forwarding.
Cisco ASA, Cisco ASASM, and Cisco FWSM Firewalls
Mitigation: ICMP Inspection
For MS13-064 and MS13-065, by using the the protocol inspection engine on the Cisco ASA 5500 Series Adaptive Security Appliances, Cisco 6500 Series ASA Services Modules, and the Cisco Firewall Services Module, administrators can configure Layer 3/Layer 4 inspection using class maps and policy maps. These methods can help protect against specific vulnerabilities, such as CVE-2013-3182 and CVE-2013-3183. The following ICMP inspection configuration uses the Cisco Modular Policy Framework (MPF) to create a policy for inspection of ICMP traffic. The ICMP inspection policy will drop connections where the ICMPv6 packets are not responding to legitimate ICMPv6 requests. For the following configuration, the assumption is that ICMPv6 packets initiated from the outside interface destined to vulnerable devices inside the firewall are configured to be dropped by the access list applied to the outside interface.
! !-- Configure ICMP inspection to drop ICMP packets associated !-- with MS13-064 and MS13-065 ! policy-map global_policy class inspection_default inspect icmp inspect icmp error service-policy global_policy globalAdditional information about application layer protocol inspection is in the Using Modular Policy Framework section of the Cisco ASA 5500 Series Configuration Guide using the CLI, 8.2 and the Configuring a Service Policy section of the Cisco Catalyst 6500 Series ASA Services Module CLI Configuration Guide, 8.4.
Identification: ICMP Inspection
Firewall syslog message 106014 will be generated when an access list denies an ICMPv6 packet. The syslog message will identify the corresponding ICMPv6 type and code as well as the source and destination of the packet dropped. For more information, see Cisco ASA 5500 Series System Log Message, 8.2 - 415006.
Firewall syslog messages 313004 and 313005 will be generated when an ICMP message is dropped by security checks added by the stateful ICMP feature. These messages are usually either ICMP echo replies without a valid echo request already passed across the ASA or ICMP error messages that are not related to any TCP, UDP, or ICMP session already established in the firewall. For more information, see Cisco ASA 5500 Series System Log Message, 8.2 - 313004.
Firewall syslog message 313009 will be generated when an ICMP message is dropped by the security checks added by the stateful ICMP feature. These messages are usually either ICMP echo replies without a valid echo request already passed across the ASA or ICMP error messages not related to any TCP, UDP, or ICMP session already established in the firewall. For more information, see Cisco ASA 5500 Series System Log Message, 8.2 - 313009.
Information about configuring syslog for the Cisco ASA 5500 Series Adaptive Security Appliance is in Monitoring - Configuring Logging. Information about configuring syslog for the Cisco Catalyst 6500 Series ASA Services Module is in Configuring Logging. Information about configuring syslog on the FWSM for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers is in Monitoring the Firewall Services Module.
In the following example, the show logging | grep icmp|ICMP command extracts syslog messages from the logging buffer on the firewall. These messages provide additional information about denied packets that could indicate attempts to exploit these vulnerabilities. Administrators can use different regular expressions with the grep keyword to search for specific data in the logged messages.
firewall#show logging | grep icmp|ICMP Aug 13 2013 14:35:54: %ASA-3-106014: Deny inbound icmp src outside:2001:db8:1:100::1 dst inside:2001:db8:60::1 (type 1, code 0)] Aug 13 2013 14:35:55: %ASA-4-313004:Denied ICMP type=9, from 2001:db8:1:100::1 on interface outside to inside:2001:db8:60::4 no matching sessionWith ICMP inspection enabled, the show service-policy command will identify the number of ICMP packets that are inspected and dropped by this feature. The following example shows output for show service-policy:
firewall# show service-policy Global policy: Service-policy: global_policy Class-map: inspection_default Inspect: dns preset_dns_map, packet 0, drop 0, reset-drop 0 Inspect: ftp, packet 0, drop 0, reset-drop 0 Inspect: rsh, packet 0, drop 0, reset-drop 0 Inspect: sunrpc, packet 0, drop 0, reset-drop 0 Inspect: tftp, packet 0, drop 0, reset-drop 0 tcp-proxy: bytes in buffer 0, bytes dropped 0 Inspect: icmp, packet 110, drop 20, reset-drop 0 Inspect: icmp error, packet 20, drop 11, reset-drop 0In the preceding example, 130 ICMP packets have been inspected and 31 packets have been dropped.
Mitigation: Application Layer Protocol Inspection
Application layer protocol inspection is available beginning in software release 7.2(1) for the Cisco ASA 5500 Series Adaptive Security Appliance, software release 8.5 for the Cisco Catalyst 6500 Series ASA Services Module, and in software release 4.0(1) for the Cisco Firewall Services Module. This advanced security feature performs deep packet inspection of traffic that transits the firewall. Administrators may construct an inspection policy for applications that require special handling through the configuration of inspection class maps and inspection policy maps, which are applied by means of a global or interface service policy.
Additional information about application layer protocol inspection is in the Configuring Application Layer Protocol Inspection section of the Cisco ASA 5500 Series Configuration Guide using the CLI, 8.2 and the Configuring Application Inspection section of the Cisco Catalyst 6500 Series ASA Services Module CLI Configuration Guide, 8.5.
Caution: Application layer protocol inspection will decrease firewall performance. Administrators are advised to test performance impact in a lab environment before this feature is deployed in production environments.
HTTP Application Inspection
For MS13-060, by using the HTTP inspection engine on the Cisco ASA 5500 Series Adaptive Security Appliances, Cisco 6500 Series ASA Services Modules, and the Cisco Firewall Services Module, administrators can configure regular expressions (regexes) for pattern matching and construct inspection class maps and inspection policy maps. These methods can help protect against specific vulnerabilities, such as CVE-2013-3181, and other threats that may be associated with HTTP traffic. The following HTTP application inspection configuration uses the Cisco Modular Policy Framework (MPF) to create a policy for inspection of traffic on TCP ports 80, 3128, 8000, 8010, 8080, 8888, and 24326, which are the default ports for the Cisco IPS #WEBPORTS variable. The HTTP application inspection policy will drop connections where the HTTP response body contains any of the regexes that are configured to match the ActiveX control that is associated with these vulnerabilities.Caution: The configured regexes can match text strings at any location in the body of an HTML response. Care should be taken to ensure that legitimate business applications that use matching text strings without calling the ActiveX control are not affected. Additional information about regex syntax is in Creating a Regular Expression.
Additional information about ActiveX exploits and mitigations that use Cisco firewall technologies is available in the Preventing ActiveX Exploits with Cisco Firewall Application Layer Protocol Inspection Cisco Security Intelligence Operations white paper.
! !-- Configure a case-insensitive (upper and lower case) regex !-- that matches the file extension of ".eot" that is typically !-- associated with Embedded OpenType (EOT) font files that are !-- associated with MS13-060 ! regex MS13-060_regex ".+\x2e[Ee][Oo][Tt]" ! !-- Configure an object group for the default ports that !-- are used by the Cisco IPS #WEBPORTS variable, which !-- are TCP ports 80 (www), 3128, 8000, 8010, 8080, 8888, !-- and 24326 ! object-group service WEBPORTS tcp port-object eq www port-object eq 3128 port-object eq 8000 port-object eq 8010 port-object eq 8080 port-object eq 8888 port-object eq 24326 ! !-- Configure an access list that uses the WEBPORTS object !-- group, which will be used to match TCP packets that !-- are destined to the #WEBPORTS variable that is used !-- by a Cisco IPS device ! access-list Webports_ACL extended permit tcp any any object-group WEBPORTS ! !-- Configure a class that uses the above-configured !-- access list to match TCP packets that are destined !-- to the ports that are used by the Cisco IPS #WEBPORTS !-- variable ! class-map Webports_Class match access-list Webports_ACL ! !-- Configure an HTTP application inspection policy that !-- identifies, drops, and logs connections that contain !-- the regexes that are configured above ! policy-map type inspect http MS_Aug_2013_policy parameters ! !-- "body-match-maximum" indicates the maximum number of !-- characters in the body of an HTTP message that !-- should be searched in a body match. The default value is !-- 200 bytes. A large number such as shown here may have an !-- impact on system performance. Administrators are advised !-- to test performance impact in a lab environment before !-- this command is deployed in production environments ! body-match-maximum 1380 match response body regex MS13-060_regex drop-connection log ! !-- Add the above-configured "Webports_Class" that matches !-- TCP packets that are destined to the default ports !-- that are used by the Cisco IPS #WEBPORTS variable to !-- the default policy "global_policy" and use it to !-- inspect HTTP traffic that transits the firewall ! policy-map global_policy class Webports_Class inspect http MS_Aug_2013_policy ! !-- By default, the policy "global_policy" is applied !-- globally, which results in the inspection of !-- traffic that enters the firewall from all interfaces ! service-policy global_policy global
For additional information about the configuration and use of object groups, reference the Cisco ASA 5500 Series Configuration Guide using the CLI, 8.2 for Configuring Object Groups and the Configuring Objects and Access Lists section of the Cisco Catalyst 6500 Series ASA Services Module CLI Configuration Guide, 8.5.
Additional information about HTTP application inspection and the MPF is in the HTTP Inspection Overview section of the Cisco ASA 5500 Series Configuration Guide using the CLI, 8.2.
Identification: Application Layer Protocol Inspection
Firewall syslog message 415006 will be generated when the URI matches a user-defined regular expression. The syslog message will identify the corresponding HTTP class and HTTP policy and indicate the action applied to the HTTP connection. Additional information about this syslog message is in Cisco ASA 5500 Series System Log Message, 8.2 - 415006.
Firewall syslog message 415007 will be generated when an HTTP message body matches a user-defined regular expression. The syslog message will identify the corresponding HTTP class and HTTP policy and indicate the action applied to the HTTP connection. Additional information about this syslog message is in Cisco ASA 5500 Series System Log Message, 8.2 - 415007.
Information about configuring syslog for the Cisco ASA 5500 Series Adaptive Security Appliance is in Monitoring - Configuring Logging. Information about configuring syslog for the Cisco Catalyst 6500 Series ASA Services Module is in Configuring Logging. Information about configuring syslog on the FWSM for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers is in Monitoring the Firewall Services Module.
In the following example, the show logging | grep regex command extracts syslog messages from the logging buffer on the firewall. These messages provide additional information about denied packets that could indicate attempts to exploit these vulnerabilities. Administrators can use different regular expressions with the grep keyword to search for specific data in the logged messages.
Additional information about regular expression syntax is in Creating a Regular Expression.
HTTP Application Inspection
firewall#show logging | grep 415007 Aug 13 2013 14:35:54: %ASA-5-415007: HTTP - matched match response body regex MS13-060_regex in policy-map MS_Aug_2013_policy, Body matched - Dropping connection from inside:192.168.60.85/2130 to outside:192.0.2.63/80 Aug 13 2013 14:35:55: %ASA-5-415007: HTTP - matched match response body regex MS13-060_regex in policy-map MS_Aug_2013_policy, Body matched - Dropping connection from inside:192.168.60.86/2133 to outside:192.0.2.63/80With HTTP application inspection enabled, the show service-policy inspect protocol command will identify the number of HTTP packets that are inspected and dropped by this feature. The following example shows output for show service-policy inspect http:
firewall# show service-policy inspect http Global policy: Service-policy: global_policy Class-map: inspection_default Class-map: Webports_Class Inspect: http MS_Aug_2013_policy, packet 5025, drop 20, reset-drop 0 protocol violations packet 0 match response body regex MS13-060_regex drop-connection log, packet 13In the preceding example, 5025 HTTP packets have been inspected and 13 HTTP packets have been dropped.
Cisco ACE
Mitigation: Application Protocol Inspection
Application protocol inspection is available for the Cisco ACE Application Control Engine Appliance and Module. This advanced security feature performs deep packet inspection of traffic that transits the Cisco ACE device. Administrators can construct an inspection policy for applications that require special handling through the configuration of inspection class maps and inspection policy maps, which are applied via a global or interface service policy.
Additional information about application protocol inspection is in the Configuring Application Protocol Inspection section of the Cisco ACE 4700 Series Appliance Security Configuration Guide.
HTTP Deep Packet Inspection
To conduct HTTP deep packet inspection for MS13-060, administrators can configure regular expressions (regexes) for pattern matching and construct inspection class maps and inspection policy maps. These methods can help protect against specific vulnerabilities, such as CVE-2013-3181, and other threats that may be associated with HTTP traffic. The following HTTP application protocol inspection configuration inspects traffic on TCP ports 80, 3128, 8000, 8010, 8080, 8888, and 24326, which are the default ports for the Cisco IPS #WEBPORTS variable. The HTTP application protocol inspection policy will drop connections where the HTTP content contains any of the regexes that are configured to match the ActiveX control that is associated with these vulnerabilities.
Caution: The configured regexes can match text strings at any location in the content of an HTML packet. Care should be taken to ensure that legitimate business applications that use matching text strings without calling the ActiveX control are not affected.
Additional information about ActiveX exploits and mitigations that use the Cisco ACE Application Control Engine Appliance and Module is available in the Preventing ActiveX Exploits with Cisco Application Control Engine Application Layer Protocol Inspection Cisco Security Intelligence Operations white paper.
! !-- Configure an HTTP application inspection class that !-- looks for HTTP packets that contain the regexes !-- that are associated with this vulnerability: !-- MS10-091 File Extension: regex matches the file !-- extension of ".eot" that is typically associated !-- with Embedded OpenType (EOT) font files ! class-map type http inspect match-any MS13-060-class match url .*.+\x2e[Ee][Oo][Tt].* ! !-- Configure an HTTP application inspection policy that !-- identifies, resets, and logs connections that contain !-- the regexes that are configured above ! policy-map type inspect http all-match MS_Aug_2013 class MS13-060-class reset log ! !-- Configure an access list that matches TCP packets !-- that are destined to the #WEBPORTS variable that is !-- used by a Cisco IPS device ! access-list WEBPORTS line 8 extended permit tcp any any eq www access-list WEBPORTS line 16 extended permit tcp any any eq 3128 access-list WEBPORTS line 24 extended permit tcp any any eq 8000 access-list WEBPORTS line 32 extended permit tcp any any eq 8010 access-list WEBPORTS line 40 extended permit tcp any any eq 8080 access-list WEBPORTS line 48 extended permit tcp any any eq 8888 access-list WEBPORTS line 56 extended permit tcp any any eq 24326 ! !-- Configure a Layer 4 class that uses the above-configured !-- access list to match TCP packets that are destined !-- to the ports that are used by the Cisco IPS #WEBPORTS !-- variable ! class-map match-all L4_http_class match access-list WEBPORTS ! !-- Configure a Layer 4 policy that applies the HTTP application !-- inspection policy configured above to TCP packets that !-- are destined to the ports that are used by the Cisco IPS !-- #WEBPORTS variable ! policy-map multi-match L4_MS_Aug_2013 class L4_http_class inspect http policy MS_Aug_2013 ! !-- Apply the configuration globally across all interfaces, !-- which results in the inspection of all traffic that enters !-- the ACE ! service-policy input L4_MS_Aug_2013
Identification: Application Protocol Inspection
HTTP Deep Packet Inspection
Cisco ACE Application Control Engine syslog message 415006 will be generated when the URI matches a user-defined regular expression. The syslog message will identify the corresponding HTTP class and HTTP policy and indicate the action applied to the HTTP connection. Additional information about this syslog message is in Cisco ACE 4700 Series Appliance System Message Guide - System Message 415006.
Cisco ACE Application Control Engine syslog message 415007 will be generated when an HTTP message body matches a user-defined regular expression. The syslog message will identify the corresponding HTTP class and HTTP policy and indicate the action applied to the HTTP connection. Additional information about this syslog message is in Cisco ACE 4700 Series Appliance System Message Guide - System Message 415007.
ACE/Admin# show logging | include 415007
Aug 13 2013 15:26:43: %ACE-5-415007: HTTP - matched MS13-060-class in policy-map L4_MS_Aug_2013, Body matched - Resetting connection from vlan206:192.0.2.94/80 to vlan130:192.168.60.63/1776 Connection 0x3a Aug 13 2013 15:30:33: %ACE-5-415007: HTTP - matched MS13-060-class in policy-map L4_MS_Aug_2013, Body matched - Resetting connection from vlan206:192.0.2.94/80 to vlan130:192.168.60.63/1778 Connection 0x3cWhen HTTP deep packet inspection is enabled, the show service-policy policyname detail command will identify the number of HTTP connections that are inspected and dropped by this feature. The following example shows output for show service-policy L4_MS_Aug_2013 detail:
ACE/Admin# show service-policy L4_MS_Aug_2013 detail Status : ACTIVE Description: ----------------------------------------- Context Global Policy: service-policy: L4_MS_Aug_2013 class: L4_http_class inspect http: L7 inspect policy : MS_Aug_2013 Url Logging: DISABLED curr conns : 0 , hit count : 1 dropped conns : 0 client pkt count : 3 , client byte count: 589 server pkt count : 3 , server byte count: 547 conn-rate-limit : 0 , drop-count : 0 bandwidth-rate-limit : 0 , drop-count : 0 L4 policy stats: Total Req/Resp: 4 , Total Allowed: 2 Total Dropped : 2 , Total Logged : 0 L7 Inspect policy : MS_Aug_2013 class/match : MS13-060-class Inspect action : reset log Total Inspected : 2 , Total Matched: 1 Total Dropped OnError: 0In the preceding example, 2 HTTP connections have been inspected and 1 HTTP connection has been dropped.
Additional information about HTTP Deep Packet Inspection and Application Protocol Inspection is in the Configuring Application Protocol Inspection section of the Cisco ACE 4700 Series Appliance Security Configuration Guide.
Cisco Intrusion Prevention System
Mitigation: Cisco IPS Signature Event Actions
Administrators can use the Cisco IPS appliances and services modules to provide threat detection and help prevent attempts to exploit several of the vulnerabilities described in this document. The following table provides an overview of CVE identifiers and the respective Cisco IPS signatures that will trigger events on potential attempts to exploit these vulnerabilities.
CVE ID Signature Release Signature ID Signature Name Enabled Severity Fidelity* CVE-2013-3182 S734 2600/0 Windows 2012 Server Denial of Service Vulnerability Yes Hgh 95 CVE-2013-3189 S734 2610/0 Microsoft Internet Explorer Remote Code Execution Yes High 80 CVE-2013-3199 S734 2633/0 Microsoft Internet Explorer Remote Memory Corruption Yes High 85 CVE-2013-3181 S734 2634/0 Microsoft Internet Explorer Remote Memory Corruption Yes High 85 CVE-2013-3193 S734 2637/0 Microsoft Internet Explorer Memory Corruption Yes High 85 CVE-2013-3194 S734 2638/0 Microsoft Internet Explorer Memory Corruption Yes High 85 CVE-2013-3184 S734 2639/0 Microsoft Windows Internet Explorer Memory Corruption Yes High 85 CVE-2013-3188 S734 31337/0 Microsoft Internet Explorer Remote Code Execution Yes High 85 CVE-2013-3191 S734 2647/0 Microsoft Internet Explorer Memory Corruption Vulnerability Yes High 90 CVE-2013-1307 S734 2646/0 Microsoft Internet Explorer Use After Free Vulnerability Yes High 90 * Fidelity is also referred to as Signature Fidelity Rating (SFR) and is the relative measure of the accuracy of the signature (predefined). The value ranges from 0 through 100 and is set by Cisco Systems, Inc.
Administrators can configure Cisco IPS sensors to perform an event action when an attack is detected. The configured event action performs preventive or deterrent controls to help protect against an attack that is attempting to exploit the vulnerabilities listed in the preceding table.
Exploits that use spoofed IP addresses may cause a configured event action to inadvertently deny traffic from trusted sources.
Cisco IPS sensors are most effective when deployed in inline protection mode combined with the use of an event action. Automatic Threat Prevention for Cisco IPS 7.x and 6.x sensors that are deployed in inline protection mode provides threat prevention against an attack that is attempting to exploit the vulnerability that is described in this document. Threat prevention is achieved through a default override that performs an event action for triggered signatures with a riskRatingValue greater than 90.
For additional information about the risk rating and threat rating calculation, reference Risk Rating and Threat Rating: Simplify IPS Policy Management.
Cisco IPS Signature Event Data
The following data has been compiled through remote monitoring services provided by the Cisco Remote Management Services team from a sample group of Cisco IPS sensors running Cisco IPS Signature Update version S734 or greater. The purpose of this data is to provide visibility into attempts to exploit the vulnerabilities released as part of the Microsoft August Security Update released on August 13, 2013. This data was gathered from events triggered on August 19, 2013.
CVE ID Signature ID Percentage of Sensors Reporting the Signature Percentage of Sensors Reporting the Signature Among Top Ten Most-Seen Events CVE-2013-3182 2600/0 0 0 CVE-2013-3189 2610/0 0 0 CVE-2013-3199 2633/0 0 0 CVE-2013-3181 2634/0 0 0 CVE-2013-3193 2637/0 0 0 CVE-2013-3194 2638/0 0 0 CVE-2013-3184 2639/0 0 0 CVE-2013-3188 31337/0 0 0 CVE-2013-3191 2647/0 0 0 CVE-2013-1307 2646/0 0 0
Cisco Security Manager
Identification: Cisco Security Manager
Cisco Security Manager, Event Viewer
Beginning in software version 4.0, Cisco Security Manager can collect syslogs from Cisco firewalls and Cisco IPS devices and provides the Event Viewer, which can query for events that are related to the vulnerabilities that are described in this document.
Using the IPS Alert Events predefined view in the Event Viewer, the user can enter the search string
- 2600/0
- 2610/0
- 2633/0
- 2634/0
- 2637/0
- 2638/0
- 2639/0
- 31337/0
in the event filter to return all captured events related to Cisco IPS signature
- 2600/0
- 2610/0
- 2633/0
- 2634/0
- 2637/0
- 2638/0
- 2639/0
- 31337/0
An Event Type ID filter can be used with the Firewall Denied Events predefined view in the Event Viewer to filter the syslog IDs shown in the following list to provide all captured Cisco firewall deny syslog messageASA-4-415007 (HTTP inspection) that could indicate potential attempts to exploit the vulnerabilities that are described in this document.
For more information about Cisco Security Manager Events, refer to the Filtering and Querying Events section of the Cisco Security Manager User Guide.
Cisco Security Manager Report Manager
Beginning in software version 4.1, Cisco Security Manager supports the Report Manager, the Cisco IPS event reporting feature. This feature allows an administrator to define reports based on Cisco IPS events of interest. Reports can be scheduled or users can run ad hoc reports as required.
Using the Report Manager, the user can define an IPS Top Signatures report for Cisco IPS devices of interest based on time-range and signature characteristics. When the Signature ID is set to
- 2600/0
- 2610/0
- 2633/0
- 2634/0
- 2637/0
- 2638/0
- 2639/0
- 31337/0
For more information about Cisco Security Manager IPS Event Reporting refer to the Understanding IPS Top Reports section of the Cisco Security Manager User Guide.
Identification: Event Management System Partner Events
Cisco works with industry-leading Security Information and Event Management (SIEM) companies through the Cisco Developer Network. This partnership helps Cisco deliver validated and tested SIEM systems that address business concerns such as long-term log archiving and forensics, heterogeneous event correlation, and advanced compliance reporting. Security Information and Event Management partner products can be leveraged to collect events from Cisco devices and then query the collected events for the incidents created by a Cisco IPS signature or deny syslog messages from firewalls that could indicate potential attempts to exploit the vulnerabilities that are described in this document. The queries can be made by Sig ID and Syslog ID as shown in the following list:
- 2600/0 Windows 2012 Server Denial of Service Vulnerability
- 2610/0 Microsoft Internet Explorer Remote Code Execution
- 2633/0 Microsoft Internet Explorer Remote Memory Corruption
- 2634/0 Microsoft Internet Explorer Remote Memory Corruption
- 2637/0 Microsoft Internet Explorer Remote Code Execution
- 2638/0 Microsoft Internet Explorer Memory Corruption
- 2639/0 Microsoft Windows Internet Explorer Memory Corruption
- 31337/0 Microsoft Internet Explorer Remote Code Execution
- ASA-4-415007 (HTTP inspection)
For more information about SIEM partners, refer to the Security Management System website.
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THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
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Show LessVersion Description Section Date 3 IPS signature event data from Cisco Remote Management Services is available for IPS signatures from August 19, 2013. 2013-August-26 13:38 GMT 2 IPS signature event data from Cisco Remote Management Services is available for IPS signatures from August 15, 2013. 2013-August-16 20:27 GMT 1 Cisco Applied Mitigation Bulletin initial public release 2013-August-13 18:10 GMT
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Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.
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The security vulnerability applies to the following combinations of products.
Primary Products Microsoft, Inc. Internet Explorer 6.0 (Base) | 7.0 (Base) | 8.0 (Base) | 9.0 (Base) | 10.0 (Base) Windows 7 for 32-bit systems (SP1) | for x64-based systems (SP1) Windows 8 for 32-bit systems (Base) | for x64-based systems (Base) Windows RT Original Release (Base) Windows Server 2003 Datacenter Edition (SP2) | Datacenter Edition, 64-bit (Itanium) (SP2) | Datacenter Edition x64 (AMD/EM64T) (SP2) | Enterprise Edition (SP2) | Enterprise Edition, 64-bit (Itanium) (SP2) | Enterprise Edition x64 (AMD/EM64T) (SP2) | Standard Edition (SP2) | Standard Edition, 64-bit (Itanium) (SP2) | Standard Edition x64 (AMD/EM64T) (SP2) | Web Edition (SP2) Windows Server 2008 Datacenter Edition (SP2) | Datacenter Edition, 64-bit (SP2) | Itanium-Based Systems Edition (SP2) | Enterprise Edition (SP2) | Enterprise Edition, 64-bit (SP2) | Essential Business Server Standard (SP2) | Essential Business Server Premium (SP2) | Essential Business Server Premium, 64-bit (SP2) | Standard Edition (SP2) | Standard Edition, 64-bit (SP2) | Web Server (SP2) | Web Server, 64-bit (SP2) Windows Server 2008 R2 x64-Based Systems Edition (SP1) | Itanium-Based Systems Edition (SP1) Windows Server 2012 Original Release (Base) Windows Vista Home Basic (SP2) | Home Premium (SP2) | Business (SP2) | Enterprise (SP2) | Ultimate (SP2) | Home Basic x64 Edition (SP2) | Home Premium x64 Edition (SP2) | Business x64 Edition (SP2) | Enterprise x64 Edition (SP2) | Ultimate x64 Edition (SP2) Oracle Corporation Oracle Fusion Middleware 8.3 (.7) | 8.4 (.0, .1)
Associated Products Microsoft, Inc. Exchange Server 2007 (SP3) | 2010 (SP2) | 2013 (CU1, CU2) Windows 7 for 32-bit systems | for x64-based systems Windows 8 for 32-bit systems | for x64-based systems Windows RT Original Release Windows Server 2003 Datacenter Edition | Datacenter Edition, 64-bit (Itanium) | Datacenter Edition x64 (AMD/EM64T) | Enterprise Edition | Enterprise Edition, 64-bit (Itanium) | Enterprise Edition x64 (AMD/EM64T) | Standard Edition | Standard Edition, 64-bit (Itanium) | Standard Edition x64 (AMD/EM64T) | Web Edition Windows Server 2008 Datacenter Edition | Datacenter Edition, 64-bit | Itanium-Based Systems Edition | Enterprise Edition | Enterprise Edition, 64-bit | Essential Business Server Standard | Essential Business Server Premium | Essential Business Server Premium, 64-bit | Standard Edition | Standard Edition, 64-bit | Web Server | Web Server, 64-bit Windows Server 2008 R2 x64-Based Systems Edition | Itanium-Based Systems Edition Windows Server 2012 Original Release Windows Vista Home Basic | Home Premium | Business | Enterprise | Ultimate | Home Basic x64 Edition | Home Premium x64 Edition | Business x64 Edition | Enterprise x64 Edition | Ultimate x64 Edition
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THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products