Symantec security products hit by high-risk flaw

Symantec's antivirus software contains a vulnerability that could be exploited by a malicious hacker to take control of a system, the company admitted late on Tuesday.

According to Symantec the bug, which affects a range of the company's security products, is a "high" risk, while the Danish security specialists Secunia have labelled it as "highly critical".

According to an advisory issued by Secunia, the bug affects most of Symantec's products, including enterprise and home user versions of Symantec AntiVirus, Symantec Norton AntiVirus and Symantec Norton Internet Security, across both the Windows and Macintosh platforms.

The vulnerability is within Symantec AntiVirus Library, which provides file format support for virus analysis. "During decompression of RAR files, Symantec is vulnerable to multiple heap overflows allowing attackers complete control of the system(s) being protected," said security consultant Alex Wheeler, who first discovered the flaw. "These vulnerabilities can be exploited remotely, without user interaction, in default configurations through common protocols such as SMTP."

RAR is a native format for WinRAR, which is used to compress and decompress data. So far the vulnerability has been reported in Dec2Rar.dll version 3.2.14.3 and, according to Wheeler, potentially affects all Symantec products that use the DLL. The full list of products affected can be seen here.

Symantec has not yet released a patch to address this problem. In the meantime, Wheeler recommends that users "disable scanning of RAR compressed files until the vulnerable code is fixed".

This is not the first vulnerability that Wheeler has discovered. In October, he highlighted a similar flaw in Kaspersky Labs' antivirus software which was later acknowledged by the company. Again it was a heap overflow vulnerability.

In February he signalled a different heap overflow vulnerability in Symantec's antivirus software.