RealPlayer Zero-Day Actively Being Exploited

Via Computerworld.com -

October 19, 2007 (Computerworld) -- Attackers are exploiting a zero-day vulnerability in RealPlayer in order to infect Windows machines running Internet Explorer, Symantec Corp. said late Thursday. The security company issued an alert that rated the threat with its highest possible score.

According to a warning issued to customers of its DeepSight threat network, Symantec said an ActiveX control installed by RealNetworks Inc.'s RealPlayer program is flawed. When combined with Microsoft Corp.'s Internet Explorer (IE) browser -- which relies on ActiveX controls to extend its functionality -- the bug can be exploited and malicious code downloaded to any PC that wanders to a specially crafted site.

Only systems on which both RealPlayer and IE have been installed are vulnerable.

Symantec ranked the attack as a "10" on its urgency scale because it has confirmed that attacks are being conducted in the wild; those attacks have resulted in malicious code downloaded to victimized PCs. The only bright spot: "We are not currently aware of widespread exploitation of this issue," the company's warning read. In another section of the advisory, it listed just two IP addresses that it has found hosting exploits of the RealPlayer bug.

Multiple versions of RealPlayer install the ActiveX control, including the current 10.5 and the beta of Version 11. RealNetworks has not released a fix, but Symantec said it had informed the media player's maker of the bug.

"Attacks that exploit this issue may get delivered to a victim through various means, most typically, though, this style of attack is carried out through malicious Web content," said Symantec. "For example, the exploit could be embedded in the HTML of advertisements that are published on trusted Web sites, or could be embedded as an IFrame in a compromised Web domain."