A vulnerability exists in the Cisco Firewall Services Module (FWSM) for the Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers that may cause the Cisco FWSM to reload after processing a malformed Skinny Client Control Protocol (SCCP) message. The vulnerability exists when SCCP inspection is enabled. Cisco has released software updates that address this vulnerability. This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100217-fwsm.
A vulnerability exists in the Cisco Firewall Services Module (FWSM) for the Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers that may cause the Cisco FWSM to reload after processing a malformed Skinny Client Control Protocol (SCCP) message. The vulnerability exists when SCCP inspection is enabled.
Cisco has released software updates that address this vulnerability.
This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100217-fwsm.
All non-fixed 4.x versions of Cisco FWSM Software are affected by this vulnerability if SCCP inspection is enabled. SCCP inspection is enabled by default.
To check if SCCP inspection is enabled, issue the show service-policy | include skinny command and confirm that the command returns output. Example output follows:
Vulmon
fwsm#show service-policy | include skinny
Inspect: skinny , packet 0, drop 0, reset-drop 0
Alternatively, a device that has SCCP inspection enabled has a configuration similar to the following:
class-map inspection_default match default-inspection-traffic ! policy-map global_policy class inspection_default ... inspect skinny ... ! service-policy global_policy global
To determine the version of Cisco FWSM Software that is running, issue the show module command-line interface (CLI) command from Cisco IOS Software or Cisco Catalyst Operating System Software to identify what modules and sub modules are installed on the system.
The following example shows a system with a Cisco FWSM (WS-SVC-FWM-1) installed in slot 2:
switch>show module Mod Ports Card Type Model Serial No. --- ----- -------------------------------------- ------------------ ----------- 1 16 SFM-capable 16 port 1000mb GBIC WS-X6516-GBIC SAL06334NS9 2 6 Firewall Module WS-SVC-FWM-1 SAD10360485 3 8 Intrusion Detection System WS-SVC-IDSM-2 SAD0932089Z 4 4 SLB Application Processor Complex WS-X6066-SLB-APC SAD093004BD 5 2 Supervisor Engine 720 (Active) WS-SUP720-3B SAL0934888E Mod MAC addresses Hw Fw Sw Status --- ---------------------------------- ------ ------------ ------------ ------- 1 0009.11e3.ade8 to 0009.11e3.adf7 5.1 6.3(1) 8.5(0.46)RFW Ok 2 0018.ba41.5092 to 0018.ba41.5099 4.0 7.2(1) 3.2(2)10 Ok 3 0014.a90c.9956 to 0014.a90c.995d 5.0 7.2(1) 5.1(6)E1 Ok 4 0014.a90c.66e6 to 0014.a90c.66ed 1.7 4.2(3) Ok 5 0013.c42e.7fe0 to 0013.c42e.7fe3 4.4 8.1(3) 12.2(18)SXF1 Ok [...]
After locating the correct slot, issue the show module <slot number> command to identify the software version that is running. Example output follows:
switch>show module 2 Mod Ports Card Type Model Serial No. --- ----- -------------------------------------- ------------------ ----------- 2 6 Firewall Module WS-SVC-FWM-1 SAD10360485 Mod MAC addresses Hw Fw Sw Status --- ---------------------------------- ------ ------------ ------------ ------- 2 0018.ba41.5092 to 0018.ba41.5099 4.0 7.2(1) 3.2(2)10 Ok [...]
The preceding example shows that the FWSM is running software version 3.2(2)10 as indicated by the column under "Sw."
Note: Recent versions of Cisco IOS Software will show the software version of each module in the output from the show module command; therefore, executing the show module <slot number> command is not necessary.
If a Virtual Switching System (VSS) is used to allow two physical Cisco Catalyst 6500 Series Switches to operate as a single logical virtual switch, the show module switch all command can display the software version of all FWSMs that belong to switch 1 and switch 2. The output from this command will be similar to the output from the show module <slot number> but will include module information for the modules in each switch in the VSS.
Alternatively, version information can be obtained directly from the FWSM through the show version command. Example output follows:
FWSM> show version FWSM Firewall Version 3.2(2)10 [...]
Customers who use the Cisco Adaptive Security Device Manager (ASDM) to manage their devices can find the version of the software displayed in the table in the login window or in the upper left corner of the ASDM window. The version notation is similar to the following example.
FWSM Version: 3.2(2)10
The Cisco ASA 5500 Series Adaptive Security Appliances are affected by the vulnerability in this advisory. A separate Cisco Security Advisory has been published to disclose this and other vulnerabilities that affect the Cisco ASA 5500 Series Adaptive Security Appliances. The advisory is available at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100217-asa.
With the exception of Cisco ASA 5500 Series Adaptive Security Appliances, no other Cisco products are currently known to be affected by this vulnerability.
The Cisco FWSM is a high-speed, integrated firewall module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers. The FWSM offers firewall services with stateful packet filtering and deep packet inspection.
The Cisco FWSM is affected by a vulnerability that may cause the device to reload during the processing of a malformed SCCP message when SCCP inspection is enabled.
This vulnerability is only triggered by transit traffic; traffic that is destined to the device does not trigger this vulnerability.
This issue is documented in Cisco bug ID CSCtb60485 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2010-0151.
If SCCP inspection is not required, this vulnerability can be mitigated by disabling it. Administrators can disable SCCP inspection by issuing the no inspect skinny command in class configuration sub-mode within the policy map configuration. If SCCP inspection is required, there are no workarounds.
When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.
In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance.
Each row of the Cisco FWSM Software table below describes a major Cisco FWSM Software train and the earliest possible release within that train that contains the fix (the "First Fixed Release") and the anticipated date of availability (if not currently available) in the "First Fixed Release" column. A device running a release that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable. The release should be upgraded at least to the indicated release or a later version (greater than or equal to the First Fixed Release label).
|
Major Release |
First Fixed Release |
|
3.1 |
Not affected |
|
3.2 |
Not affected |
|
4.0 |
4.0(8) |
Fixed Cisco FWSM Software can be downloaded from the Software Center on Cisco.com by visiting http://www.cisco.com/cisco/web/download/index.html and navigating to Security > Cisco Catalyst 6500 Series Firewall Services Module > Firewall Services Module (FWSM) Software.
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory.
This vulnerability was discovered during the resolution of customer service requests.
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.
|
Revision 1.0 |
2010-February-17 |
Initial public release. |
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