channels/chan_sip.c in Asterisk Open Source 1.8.x before 1.8.13.1 and 10.x before 10.5.2, Asterisk Business Edition C.3.x before C.3.7.5, Certified Asterisk 1.8.11-certx before 1.8.11-cert4, and Asterisk Digiumphones 10.x.x-digiumphones before 10.5.2-digiumphones does not properly handle a provisional response to a SIP reINVITE request, which allows remote authenticated users to cause a denial of service (RTP port exhaustion) via sessions that lack final responses.

The remote host is affected by the vulnerability described in GLSA-201209-15 (Asterisk: Multiple vulnerabilities)

    Multiple vulnerabilities have been found in Asterisk:
      An error in manager.c allows shell access (CVE-2012-2186).
      An error in Asterisk could cause all RTP ports to be exhausted         (CVE-2012-3812).
      A double-free error could occur when two parties attempt to         manipulate the same voicemail account simultaneously (CVE-2012-3863).
      Asterisk does not properly implement certain ACL rules         (CVE-2012-4737).
  Impact :

    A remote, authenticated attacker could execute arbitrary code with the       privileges of the process, cause a Denial of Service condition, or bypass       outbound call restrictions.
  Workaround :

    There is no known workaround at this time.

Several vulnerabilities were discovered in Asterisk, a PBX and telephony toolkit, allowing privilege escalation in the Asterisk Manager, denial of service or privilege escalation.

More detailed information can be found in the Asterisk advisories:
AST-2012-010, AST-2012-011, AST-2012-012, and AST-2012-013.

The Asterisk Development Team has announced security releases for Certified Asterisk 1.8.11 and Asterisk 1.8 and 10. The available security releases are released as versions 1.8.11-cert4, 1.8.13.1, 10.5.2, and 10.5.2-digiumphones.

These releases are available for immediate download at http://downloads.asterisk.org/pub/telephony/asterisk/releases

The release of Asterisk 1.8.11-cert4, 1.8.13.1, 10.5.2, and 10.5.2-digiumphones resolve the following two issues :

  - If Asterisk sends a re-invite and an endpoint responds     to the re-invite with a provisional response but never     sends a final response, then the SIP dialog structure is     never freed and the RTP ports for the call are never     released. If an attacker has the ability to place a     call, they could create a denial of service by using all     available RTP ports.

  - If a single voicemail account is manipulated by two     parties simultaneously, a condition can occur where     memory is freed twice causing a crash.

These issues and their resolution are described in the security advisories.

For more information about the details of these vulnerabilities, please read security advisories AST-2012-010 and AST-2012-011, which were released at the same time as this announcement.

For a full list of changes in the current releases, please see the ChangeLogs :

http://downloads.asterisk.org/pub/telephony/certified-asterisk/release s/ChangeLog-1.8.11-cert4 http://downloads.asterisk.org/pub/telephony/asterisk/releases/ChangeLo g-1.8.13.1 http://downloads.asterisk.org/pub/telephony/asterisk/releases/ChangeLo g-10.5.2 http://downloads.asterisk.org/pub/telephony/asterisk/releases/ChangeLo g-10.5.2-digiumphones

The security advisories are available at :

  -     http://downloads.asterisk.org/pub/security/AST-2012-010.
    pdf

    -       http://downloads.asterisk.org/pub/security/AST-2012-01       1.pdf

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the version in its SIP banner, the version of Asterisk running on the remote host is potentially affected by a vulnerability that could allow a remote, authenticated attacker to exhaust the server of resources.

If an endpoint sends a provisional response to the server's re-INVITE message, certain data structures are not freed. More iterations of this sequence lead to exhaustion of all available RTP ports.

ID	Name	Product	Family	Severity
62344	GLSA-201209-15 : Asterisk: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
62188	Debian DSA-2550-2 : asterisk - several vulnerabilities	Nessus	Debian Local Security Checks	high
60069	Fedora 17 : asterisk-10.5.2-1.fc17 (2012-10324)	Nessus	Fedora Local Security Checks	medium
60064	Asterisk Endpoint Provisional Response Parsing RTP Port Consumption Remote DoS (AST-2012-010)	Nessus	Misc.	medium

Detections

Analytics

CVE-2012-3863

medium

Tenable Plugins

high

high

medium

medium