Vulnerability Note VU#305272

Symantec RAR decompression library contains multiple heap overflows

Original Release date: 21 Dec 2005 | Last revised: 29 Dec 2005


The Symantec RAR decompression library Dec2RAR.dll contains multiple heap buffer overflows. Using a specially crafted RAR archive, a remote attacker could execute arbitrary code or cause a denial of service.


Symantec AntiVirus and other security products use a library to decompress and scan inside RAR archives. This library, Dec2RAR.dll, contains multiple heap buffer overflows. A remote attacker could exploit these vulnerabilities by causing a Symantec product to scan a specially crafted RAR archive. The attacker could accomplish this in a number of ways including hosting the archive on a web site, sending it as an email attachment, or providing it on a file system or network share.

The vulnerable library exists in Symantec products that run on Microsoft Windows platforms and may be present in OEM versions or other software based on Symantec code. Please see Symantec AntiVirus Decomposition Buffer Overflow (SYM05-027) for further information, including a list of affected products.


A remote attacker could execute arbitrary code or cause a denial of service. Since many scanning processes run with Local System privileges, the attacker could take complete control of a vulnerable system.


Upgrade to a fixed version as specified in Symantec AntiVirus Decomposition Buffer Overflow (SYM05-027).

Disable RAR scanning

It may be possible to filter or disable scanning of RAR archives. See Symantec AntiVirus Decomposition Buffer Overflow (SYM05-027) and Symantec AntiVirus library .rar decompression heap overflow vulnerability: Recommendations to customers for details. Depending on how the filtering mechcanism and the Symantec product identify RAR archives, it may be insufficient to rely on the file extention (.rar). Also, disabling RAR or other archive file scanning will prevent Symantec products from detecting viruses or other malicious code in those files.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Symantec, Inc.Affected20 Dec 200524 Dec 2005
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was publicly reported by The advisory credits Alex Wheeler.

This document was written by Art Manion.

Other Information

  • CVE IDs: CVE-2005-4438
  • Date Public: 20 Dec 2005
  • Date First Published: 21 Dec 2005
  • Date Last Updated: 29 Dec 2005
  • Severity Metric: 21.26
  • Document Revision: 10


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