Cisco Security Advisory
Click Icon to Copy Verbose Score
AV:R/AC:L/Au:NR/C:N/I:N/A:P/B:N/E:U/RL:O/RC:C
-
Cisco Security Agent (CSA) for Linux contains a denial of service vulnerability involving port scans. By performing a port scan against a system running a vulnerable version of CSA, it is possible to cause the system to become unresponsive. Cisco Unified CallManager (CUCM) and Cisco Unified Presence Server (CUPS) ship with a vulnerable CSA version.
There are workarounds for this vulnerability. Cisco has made free software available to address this vulnerability for affected customers.
This advisory is posted at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20061025-csa.
-
Vulnerable Products
The following CSA versions are vulnerable to the port scanning issue:
-
CSA version 4.5 for Linux (standalone and managed) prior to Hotfix
4.5.1.657
-
CSA version 5.0 for Linux (standalone and managed) prior to Hotfix
5.0.0.193
The following Cisco products include a standalone CSA for Linux version which are also vulnerable to this issue:
-
Cisco Unified CallManager (CUCM) 5.0 versions including 5.0(4) and
5.0(4a)
-
Cisco Unified Presence Server (CUPS) 1.0 versions including
1.0(2)
Products Confirmed Not Vulnerable
The following CSA Agent versions are not vulnerable to the port scanning issue:
-
CSA version 5.1 (standalone and managed) for Linux
-
All CSA versions (standalone and managed) for
Windows
-
All CSA versions (standalone and managed) for
Solaris
No other Cisco products are currently known to be affected by this vulnerability.
-
CSA version 4.5 for Linux (standalone and managed) prior to Hotfix
4.5.1.657
-
Cisco Security Agent (CSA) provides threat protection for server and desktop computing systems. CSA for Linux is vulnerable to a denial of service attack that may be triggered during the identification of network port scans. By running a port scan with specific options, it is possible to cause excessive system resource consumption resulting in a denial of service. It is possible to mitigate this vulnerability by restricting network access to vulnerable systems to trusted networks. This issue is not a Linux operating system issue. CSA versions for other operating systems (Windows, Solaris) are not affected by this vulnerability. This issue is documented in Cisco Bug ID CSCse98684 ( registered customers only) .
Cisco Unified CallManager 5.0 versions, including 5.0(4) and 5.0(4a), ship with a vulnerable version of CSA. A new CallManager Options Package (COP) file is available to update the CSA version on CallManager 5.0(4). Future versions of CallManager will include the updated CSA version. This issue is documented in Cisco Bug ID CSCse97601 ( registered customers only) .
Cisco Unified Presence Server 1.0 versions, including 1.0(2), ship with a vulnerable version of CSA. A new COP file is available to update the CSA version on CUPS 1.0(2). Future versions of CUPS will include the updated CSA version. This issue is documented in Cisco Bug ID CSCsg40052 ( registered customers only) .
-
It is possible to workaround the Linux port scan vulnerability by disabling the Netshield rule in managed agents via the CSA Management Center (CSAMC) console (not possible for standalone and CUCM/CUPS agents). Administrators should exercise caution when employing this workaround because it may open a system to additional network denial of service attacks. With the Netshield rule disabled, CSA will still provide protection against buffer overflows and other malicious activities.
-
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.
CSA for Linux
Affected Software Version
Fixed Software Version
CSA Hotfix prior to 4.5.1.657
CSA Hotfix 4.5.1.657
CSA Hotfix prior to 5.0.0.193
CSA Hotfix 5.0.0.194 *
* CSA Hotfix 5.0.0.194 deprecates CSA Hotfix 5.0.0.193.
Fixed CSA software can be downloaded at http://www.cisco.com/pcgi-bin/tablebuild.pl/csahf-crypto?psrtdcat20e2.
CUCM/CUPS
Affected Software Version
Fixed Software Version
CUCM 5.0 versions including 5.0(4) and 5.0(4a)
CUCM 5.0(4) and 5.0(4a) with CSA COP upgrade
CUPS 1.0 versions including 1.0(2)
CUPS 1.0(2) with CSA COP upgrade
The CUCM COP file (platform-csa-4.5.1-657.1.cop.sgn) and installation instructions can be downloaded at http://www.cisco.com/pcgi-bin/tablebuild.pl/cmva-3des?psrtdcat20e2.
The CUPS COP file (CUPS-1.0.2-CSA-4.5.1-657.1.i386.cop.sgn) and installation instructions can be downloaded at http://www.cisco.com/pcgi-bin/tablebuild.pl/cups-10?psrtdcat20e2.
-
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory.
This vulnerability was discovered internally by Cisco.
-
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.
-
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.
A stand-alone 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.