The FWDOWNL firmware-download implementation in Asterisk Open Source 1.0.x, 1.2.x before 1.2.30, and 1.4.x before 1.4.21.2; Business Edition A.x.x, B.x.x before B.2.5.4, and C.x.x before C.1.10.3; AsteriskNOW; Appliance Developer Kit 0.x.x; and s800i 1.0.x before 1.2.0.1 allows remote attackers to cause a denial of service (traffic amplification) via an IAX2 FWDOWNL request.

The remote host is affected by the vulnerability described in GLSA-200905-01 (Asterisk: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in the IAX2 channel     driver when performing the 3-way handshake (CVE-2008-1897), when     handling a large number of POKE requests (CVE-2008-3263), when handling     authentication attempts (CVE-2008-5558) and when handling firmware     download (FWDOWNL) requests (CVE-2008-3264). Asterisk does also not     correctly handle SIP INVITE messages that lack a 'From' header     (CVE-2008-2119), and responds differently to a failed login attempt     depending on whether the user account exists (CVE-2008-3903,     CVE-2009-0041).
  Impact :

    Remote unauthenticated attackers could send specially crafted data to     Asterisk, possibly resulting in a Denial of Service via a daemon crash,     call-number exhaustion, CPU or traffic consumption. Remote     unauthenticated attackers could furthermore enumerate valid usernames     to facilitate brute-force login attempts.
  Workaround :

    There is no known workaround at this time.

This security update fixes multiple security vulnerabilities in asterisk (CVE-2008-1897, CVE-2008-2119, CVE-2008-3263, CVE-2008-3264).

Update to 1.4.21.2 to fix CVE-2008-3263 / AST-2008-010 and CVE-2008-3264 / AST-2008-011. AST-2008-010: Asterisk IAX 'POKE' resource exhaustion - http://downloads.digium.com/pub/security/AST-2008-010.html AST-2008-011: Traffic amplification in IAX2 firmware provisioning system - http://downloads.digium.com/pub/security/AST-2008-011.html

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.

The firmware download protocol implemented in the version of Asterisk running on the remote host does not initiate a handshake.  By spoofing an IAX2 FWDOWNL request, an unauthenticated, remote attacker may be able to leverage this issue to flood a third-party host with unwanted firmware packets from the affected host.

ID	Name	Product	Family	Severity
38677	GLSA-200905-01 : Asterisk: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
33894	openSUSE 10 Security Update : asterisk (asterisk-5524)	Nessus	SuSE Local Security Checks	high
33569	Fedora 8 : asterisk-1.4.21.2-1.fc8 (2008-6676)	Nessus	Fedora Local Security Checks	high
33564	Asterisk IAX2 FWDOWNL Request Spoofing Remote DoS	Nessus	Denial of Service	medium

Detections

Analytics

CVE-2008-3264

high

Tenable Plugins

high

high

high

medium