Security experts are warning RealPlayer users to stop using Internet Explorer until a patch is released for a flaw researchers discovered which could allow code execution. Researcher Elazar Broad has posted to the Full Disclosure mailing list a so-called heap overflow vulnerability that makes it possible for an attacker to modify heap blocks after they are freed and overwrite certain registers.
This could allow code execution on a compromised machine. The vulnerability affects all versions of RealPlayer running under Internet Explorer. Exploit code for this flaw has not yet been made public.
Without a patch from RealPlayer, security experts recommend disabling the killbit for the following ActiveX ClassIDs:
- 2F542A2E-EDC9-4BF7-8CB1-87C9919F7F93
- CFCDAA03-8BE4-11CF-B84B-0020AFBBCCFA
However, disabling these killbits will also remove some functionality within the player.
To avoid the loss of functionality, security experts recommend using RealPlayer in a browser that doesn"t support ActiveX, such as Mozilla Firefox (for Windows and Mac).