The ENSURE_BITS macro in mszipd.c for Clam AntiVirus (ClamAV) 0.83, and other versions vefore 0.86, allows remote attackers to cause a denial of service (CPU consumption by infinite loop) via a cabinet (CAB) file with the cffile_FolderOffset field set to 0xff, which causes a zero-length read.

This advisory adds security support for the stable amd64 distribution.
It covers all security updates since the release of sarge, which were missing updated packages for the not yet official amd64 port. Future security advisories will include updates for this port as well.

An iDEFENSE Security Advisory reports :

Remote exploitation of an input validation error in Clam AntiVirus ClamAV allows attackers to cause a denial of service condition.

The vulnerability specifically exists due to insufficient validation on cabinet file header data. The ENSURE_BITS() macro fails to check for zero length reads, allowing a carefully constructed cabinet file to cause an infinite loop.

ClamAV is used in a number of mail gateway products. Successful exploitation requires an attacker to send a specially constructed CAB file through a mail gateway or personal anti-virus client utilizing the ClamAV scanning engine. The infinate loop will cause the ClamAV software to use all available processor resources, resulting in a denial of service or severe degradation to system performance. Remote exploitation can be achieved by sending a malicious file in an e-mail message or during an HTTP session.

A number of potential remote denial of service vulnerabilities have been identified in ClamAV. In addition to the four issues identified by CVE ID above, there are fixes for issues in libclamav/cvd.c and libclamav/message.c. Together, these issues could allow a carefully crafted message to crash a ClamAV scanner or exhaust various resources on the machine running the scanner.

The remote host is running ClamAV, an open-source antivirus solution for Unix-like systems.
This version of ClamAV is reported to be vulnerable to a flaw where the parsing of a malicious file will cause the ClamAV process to crash.  An attacker exploiting this flaw would need to be able to send a specially formed email to the system running ClamAV.  Successful exploitation would result in loss of service. 

ID	Name	Product	Family	Severity
57528	Debian DSA-773-1 : amd64 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
19139	FreeBSD : clamav -- cabinet file handling DoS vulnerability (d8e1aadd-ee68-11d9-8310-0001020eed82)	Nessus	FreeBSD Local Security Checks	low
18629	Debian DSA-737-1 : clamav - remote denial of service	Nessus	Debian Local Security Checks	medium
3033	ClamAV < 0.86.1 Content-parsing DoS (deprecated)	Nessus Network Monitor	Web Clients	medium

Detections

Analytics

CVE-2005-1923

high

Tenable Plugins

critical

low

medium

medium