18258 : Clam AntiVirus CHM File Processing Filename Overflow
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Views This Week	Views All Time	Added to OSVDB	Last Modified	Modified (since 2008)	Percent Complete
2	204	over 4 years ago	over 2 years ago	0 times	100%

Timeline

Disclosure Date
2005-07-24

Keywords

Description

A remote overflow exists in Clam AntiVirus. Clam AntiVirus fails to perform adequate boundary check in libclamav/chmunpack.c, resulting in a heap overflow. With a specially crafted request, an attacker can gain privileges equal to those of the Clam AntiVirus process, possibly allowing for a remote system compromise.

Classification

Location: Remote / Network Access
Attack Type: Input Manipulation
Impact: Loss of Integrity
Exploit: Exploit Unknown
Disclosure: OSVDB Verified

Technical

CHM processing contains an integer overflow that results in heap corruption. The following is vulnerable code from read_chunk_entries() in chmunpack.c. If length is -1, it will wrap and malloc() will return small heap buffer which is overflowed on the following strncpy().

name_len = read_enc_int(&current, end);
file_e->name = (unsigned char *) cli_malloc(name_len+1);
if (!file_e->name) {
free(file_e);
return FALSE;
}
strncpy(file_e->name, current, name_len);

Solution

Upgrade to version 0.86.2 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.

Products

Clam AntiVirus	Clam AntiVirus	0.86.1
		0.85.x
		0.84.x
		0.83.x
		0.82.x
		0.81.x
		0.80.x
		0.75.x
		0.74.x
		0.73.x
		0.72.x
		0.71.x
		0.70.x

References

Security Tracker: 1014567
Secunia Advisory ID: 16180 16229 16250 16296 16458
Related OSVDB ID: 18257 18259
CVE ID: 2005-2450 (see also: NVD)
Keyword: email integer overflow
Mail List Post: http://archives.neohapsis.com/archives/fulldisclosure/2005-07/0547.html
Other Advisory URL: http://distro.conectiva.com.br/atualizacoes/index.php?id=a&anuncio=000987
http://frontal1.mandriva.com/security/advisories?name=MDKSA-2005:125
http://www.debian.org/security/2005/dsa-776
http://www.gentoo.org/security/en/glsa/glsa-200507-25.xml
http://www.rem0te.com/public/images/clamav.pdf
Vendor Specific News/Changelog Entry: http://sourceforge.net/project/shownotes.php?release_id=344514

Tools & Filters

	19432 19886
	3108

Credit

Neel Mehta - -
Alex Wheeler - IBM ISS X-Force

CVSSv2 Score

CVSSv2 Base Score = 7.5
Source: nvd.nist.gov | Generated: 2005-08-04 | Disagree?

Blogs

This product uses the Daylife API but is not endorsed or certified by Daylife.

This section lists the latest news and blogs found via the daylife API (and for older items, the technorati API), which mention or otherwise discuss this vulnerability.

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