AOL Instant Messenger 5.5.x and earlier allows remote attackers to cause a denial of service (client crash) via an invalid smiley icon location in the sml parameter of a font tag.
The Buddy icon file for AOL Instant Messenger (AIM) 4.3 through 5.5 is created in a predictable location, which may allow remote attackers to use a shell: URI to exploit other vulnerabilities that involve predictable locations.