A flaw in Network Associates' GroupShield antivirus product has caused some users of Microsoft's Exchange 2000 e-mail server to crash, according to Vincent Gullotto, a vice-president at Avert, Network Associates' antivirus research group.
The problem affects organisations running the Exchange 2000 product with GroupShield version 5.2.
A flaw in the GroupShield product causes the Exchange information store to fail when e-mail messages are received with certain formatting characteristics in the e-mail "From" line, Gullotto said.
The problem has caused the Exchange server to stop responding, which results in the loss of e-mail service to Exchange users.
"To the users it looks like a network problem. You can't get your mail," said Scott Martin, a system administrator at software company Modular Mining Systems.
Modular Mining Systems first encountered the problem on 25 March, after using the GroupShield with Exchange 2000 for six months without incident.
Network Associates said it discovered the problem after a report from a customer in January.
The company issued a patch in January called "Hotfix 2", to repair the problem and updated its knowledge base with information about the problem at the time.
Network Associates could not say how many of its GroupShield customers have downloaded and installed the patch since January or how many are still vulnerable.
A handful of GroupShield customers reported problems, including Exchange Server crashes, resulting from the flaw since January, with a couple more incidents in recent weeks.
Despite the small number of occurrences, GroupShield is urging customers to apply Hotfix 2 to affected systems.
Paul Roberts writes for IDG News Service