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Symantec RAR decompression library contains multiple heap overflows

Vulnerability Note VU#305272

Original Release Date: 2005-12-21 | Last Revised: 2005-12-30


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.

Vendor Information

Affected   Unknown   Unaffected

Symantec, Inc.

Notified:  December 21, 2005 Updated:  December 24, 2005



Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


Please see Symantec AntiVirus Decomposition Buffer Overflow (SYM05-027).

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental 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
Severity Metric: 21.26
Date Public: 2005-12-20
Date First Published: 2005-12-21
Date Last Updated: 2005-12-30 04:53 UTC
Document Revision: 10

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.