Cisco Security Advisory
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AV:N/AC:L/Au:S/C:C/I:C/A:C/E:F/RL:OF/RC:C
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Cisco IronPort AsyncOS Software for Cisco Web Security Appliance is affected by the following vulnerabilities:
- Two authenticated command injection vulnerabilities
- Management GUI Denial of Service Vulnerability
These vulnerabilities are independent of each other; a release that is affected by one of the vulnerabilities may not be affected by the others.
Successful exploitation of any of the two command injection vulnerabilities could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system with elevated privileges.
Successful exploitation of the Management GUI Denial of Service Vulnerability could cause several critical processes to become unresponsive and make the affected system unstable.
Cisco has released software updates that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are available. This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130626-wsa
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Vulnerable Products
All models of Cisco Web Security Appliance running a vulnerable version of Cisco IronPort AsyncOS Software are affected by one or more of the vulnerabilities described in this advisory.
Some of the vulnerabilities described in this advisory affect Cisco IronPort Async OS for Cisco Content Security Management and Cisco Email Security Appliance.
Consult the Cisco security advisory Multiple Vulnerabilities in Cisco Content Security Management Appliance at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130626-sma for additional information about the vulnerabilities affecting Cisco Content Security Management Appliance and Cisco security advisory Multiple Vulnerabilities in Cisco Email Security Appliance at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130626-esa for additional information about the vulnerabilities affecting Cisco Email Security Appliance.
Determining the Running Software Version
To determine whether a vulnerable version of Cisco IronPort AsyncOS Software for Cisco Web Security is running on an appliance, administrators can issue the version command. The following example shows a device running Cisco IronPort AsyncOS Software version 7.5.1-079:
ciscowsa> version
Current Version
===============
Product: Cisco IronPort S670 Web Security Appliance
Model: S670
Version: 7.5.1-079Products Confirmed Not Vulnerable
With the exception of Cisco Content Security Management and Cisco Email Security Appliance, no other Cisco products are currently known to be affected by these vulnerabilities.
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The Cisco Web Security Appliance is a secure web gateway that combines advanced malware protection, application visibility and control (AVC), acceptable use policy controls, reporting, and secure mobility on a single platform.
Authenticated Command Injection Vulnerabilities
Two vulnerabilities in the web framework code could allow an authenticated, remote attacker to to execute arbitrary commands on the underlying operating system with elevated privileges.
The vulnerabilities are due to the failure to properly sanitize user supplied input that is utilized to perform actions that leverage the underlying command-line interface of the device. An authenticated, unprivileged attacker could exploit this vulnerability by sending a crafted URL to the affected system or convince a valid user to click on a malicious URL. An successful exploit could allow the attacker to take complete control of the affected device.
These vulnerabilities can only be triggered by IPv4 traffic directed to the management IP addresses of the affected system.
These vulnerabilities can be exploited over the default management ports, TCP port 8080 or TCP port 8443.Note: The default management ports can be reconfigured on the system.
These vulnerabilities are documented by Cisco bug IDs CSCzv69294 (registered customers only) and CSCzv85726 (registered customers only) and have been assigned Common Vulnerabilities and Exposures (CVE) IDs CVE-2013-3383 and CVE-2013-3384.
Management GUI Denial of Service Vulnerability
A vulnerability in the Graphical User Interface (GUI) function in the web framework code could allow an unauthenticated, remote attacker to cause multiple processes to become unresponsive, resulting in a denial of service condition.
The vulnerability is due to improper handling, processing and termination of HTTP and HTTPS connections. An attacker could exploit this vulnerability by sending multiple HTTP or HTTPS requests to any management enabled interfaces of the affected system. A full TCP three-way handshake is required to exploit this vulnerability. An exploit could allow the attacker prevent management access via the GUI and cause other critical process to become unresponsive, resulting in a denial of service condition. A hard reboot of the affected system is needed to restore full functionality.
This vulnerability can only be triggered by IPv4 traffic directed to the management IP addresses of the affected system. This vulnerability can be exploited over the default management ports, TCP port 8080 or TCP port 8443.Note: The default management ports can be reconfigured on the system.
This vulnerability is documented by Cisco bug ID CSCzv58669 (registered customers only) and has been assigned CVE ID CVE-2013-3385.
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All the vulnerabilities described in this security advisory can be mitigated by disabling management access to the affected system GUI.
Administrators can use the interfaceconifg command to disable appliance management via the GUI. Alternatively, this can be done via the GUI by editing the management interface properties under Network->IP interfaces-> Edit and then selecting Disable Appliance Management.
Note: Administrators can manage the affected system via SSH and command-line interface while GUI access is disabled. However, not all commands and features may be available via command-line interface.
Administrators can also limit the attack surface by restricting IP addresses that can access the management interface. This can be done using the adminaccessconfig command and selecting IPACCESS from the menu.
Administrator should also implement Cross-Site Request Forgery protection if available on their platform and software release. This will help limit the attack surface of the command injection vulnerabilities, although will not completely eliminate them.
Additional workaround details are available in the companion Applied Mitigation Bulletin (AMB) at the following location:
http://tools.cisco.com/security/center/viewAMBAlert.x?alertId=29452
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When considering software upgrades, customers are advised to consult the Cisco Security Advisories, Responses, and Notices archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
The following table lists the first fixed releases that contain fixes for the two authenticated command injection vulnerabilities:
Major Release
First Fixed In
7.1 and prior
7.1.3-033 and 7.1.4-101
7.5 7.5.0-838
7.7 7.7.0-550
The following table list the first fixed releases that contain fixes for the Management GUI Denial of Service Vulnerability:
Major Release
First Fixed In
7.1 and prior
7.1.3-033 and 7.1.4-101
7.5 7.5.0-838 and 7.5.1-201
7.7 7.7.0-602
The following table lists the recommended releases that include fixes for all the vulnerabilities in described in this security advisory:
Major Release
Recommended
7.1 and prior
7.5.1-201 or later
7.5 7.5.1-201 or later
7.7 7.7.0-602 or later
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The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
These vulnerabilities were identified during an internal security review of the affected products.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Show LessRevision 1.0 2013-June-26 Initial public release
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