Symantec Acknowledges Two Holes in Antivirus Products

Security software company Symantec has acknowledged that software flaws in some of its antivirus products could allow malicious hackers to use denial of service (DOS) attacks to crash systems running the software, disrupting automatic protection features.

The company posted a notice on its Web page Monday describing two DOS vulnerabilities in the 2004 and 2005 editions of Symantec Norton AntiVirus, Norton Internet Security, and Norton System Works. The company has patched the holes and distributed software updates to users of the LiveUpdate automatic update service, but systems that remain unpatched could be susceptible to remote attack through e-mail or the Web, Symantec said.

Who Found Them

The holes were discovered by security researchers in Japan. In one case, the Information-Technology Promotion Agency-Japan (IPA) discovered a problem on systems running Norton AntiVirus 2005 with the Auto-Protect and SmartScan features enabled. The Auto-Protect feature scans files sent from the Internet, removable disks, or e-mail attachments and looks for viruses, Trojan horse programs, and other harmful code. SmartScan allows Norton AntiVirus to quickly scan specific types of files often associated with malicious code, such as .exe and .doc files.

With SmartScan enabled, researchers at IPA found that renaming a file on a shared network folder could cause the system running Norton AntiVirus to crash.

In a second issue reported by the Japan Computer Emergency Response Team (JPCERT), machines running Norton AntiVirus 2004 and 2005 crashed when Auto-Protect scanned a specific type of file that Symantec declined to identify.

Symantec rated the two holes as "low" risks and said that it was unaware of any adverse customer impact from the vulnerabilities. Nevertheless, the company advised customers to run LiveUpdate for any affected products until all available product updates are downloaded and installed.

Not Infallible

The news comes amid numerous reports of flaws in antivirus products, which many Internet users rely on for protection against hackers, worms, and viruses.

In February, Symantec issued patches to fix a high-impact hole affecting virtually its entire product line. That hole, which was discovered by Internet Security Systems (ISS), affected the DEC2EXE module in the Symantec Anti-Virus Library, part of the company's virus detection engine. The vulnerability could allow a remote attacker to take advantage of vulnerable Symantec products to gain unauthorized access to a network or its client PCs, ISS warned.

On March 17, ISS issued another warning about a remotely exploitable hole in antivirus technology--this one involving Symantec's chief competitor, McAfee. In that case, ISS said that a stack-based buffer overflow affecting nearly all versions of VirusScan could be exploited by remote attackers without their having to log in to affected systems to launch an attack.