10 August 2009
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT Security Bulletin ASB-2009.1047 A vulnerability has been identified in Asterisk's SIP channel driver 11 August 2009 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Asterisk Open Source prior to versions 1.2.34, 22.214.171.124, 126.96.36.199, 188.8.131.52 Asterisk Business Edition prior to versions B.2.5.9, C.2.4.1, C.3.1 s800i Asterisk Appliance prior to version 184.108.40.206 Operating System: UNIX variants (UNIX, Linux, OSX) Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2009-2726 Member content until: Thursday, September 10 2009 OVERVIEW A vulnerability has been identified in Asterisk Open Source prior to versions 1.2.34, 220.127.116.11, 18.104.22.168, 22.214.171.124, Asterisk Business Edition prior to versions B.2.5.9, C.2.4.1, C.3.1 and s800i Asterisk Appliance prior to version 126.96.36.199.  IMPACT The vendor has provided the following description of the vulnerability: "On certain implementations of libc, the scanf family of functions uses an unbounded amount of stack memory to repeatedly allocate string buffers prior to conversion to the target type. Coupled with Asterisk's allocation of thread stack sizes that are smaller than the default, an attacker may exhaust stack memory in the SIP stack network thread by presenting excessively long numeric strings in various fields."  MITIGATION The vendor recommends upgrading to the latest version of Asterisk.  REFERENCES  Asterisk Project Security Advisory - AST-2009-005 http://downloads.asterisk.org/pub/security/AST-2009-005.html AusCERT has made every effort to ensure that the information contained in this document is accurate. However, the decision to use the information described is the responsibility of each user or organisation. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: firstname.lastname@example.org Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iD8DBQFKgQJANVH5XJJInbgRAgyQAJ9dWqUOCq6YD1+WxWHpSQFZDv1E+wCfbf/d CaiG21oap+GT+R7Dx8IuDk0= =xCyk -----END PGP SIGNATURE-----