The U.K.-based maker of software used to scan for viruses, spam e-mail and other forms of malicious code said that an independent researcher informed it of the issue, which specifically involves the manner in which multiple versions of Sophos Anti-Virus handle Microsoft Cabinet files, which allow for data compression.
Sophos said that by crafting a specially purposed Cabinet file meant to take advantage of the vulnerability, an attacker could execute arbitrary code on computers running certain versions of its anti-virus package. Authentication is not required to exploit the vulnerability; however, the software maker said the issue does not prevent Sophos desktop anti-virus scanner from correctly identifying viruses.
The company contends that the risk of infection related to the issue is very small, and company officials said they have not seen any examples of malicious code built to take advantage of the glitch. Sophos has already issued to its customers a software patch meant to fix the issue.
The vulnerability is present in multiple versions of Sophos Anti-Virus software for Microsoft Windows, Apple Mac OS and Linux, as well as the companys Anti-Virus Small Business Edition, PureMessage and MailMonitor gateway security applications.
While Sophos is typically on the opposite end of the vulnerability-reporting process, as it frequently highlights flaws in the products of major software makers such as Microsoft, a company spokesman said that the company appreciates people working with it to identify any problems, and that it always supports responsible disclosure of security issues.
Sophos said it was first informed of the glitch in mid-March by the TippingPoint division of 3Com, which also sponsors a research effort around vulnerability disclosure known as the Zero Day Initiative. A company spokesman said that Sophos distributed a patch for the issue to most of its customers on April 28, with all of its users receiving the update by May 5, the same week it reported the flaw publicly.
For its part, TippingPoint said it released its own fix for the Sophos problem to customers on March 14; however, the company distributed a vulnerability fix for one of its own security applications in early May related to a problem it was informed of in January.
Sophos isnt the only security software vendor battling recent reports of product vulnerabilities. During the last week in April, researchers identified a handful of flaws in anti-virus market leader Symantecs Scan Engine, which could pose the risk of unauthorized access to critical data and malicious attacks.
The problem reportedly allows attacks to be carried out through vulnerabilities in the manner that Scan Engine handles authentication data, server communications and access to its installation directory. Symantec has already issued an update for users of Scan Engine Version 126.96.36.199 or later.