The flaw in Firefox 3.5 - and the newly-released 3.5.1 - can lead to remote code execution due to a flaw in the Unicode text handler.
The first major security flaw
in the release branch of Firefox 3.5 may have been fixed, but the fun isn't over yet: another serious flaw has been discovered in the browser.
Despite being recently updated to version 3.5.1, SecurityFocus
is reporting on a stack buffer overflow vulnerability which affects both the original 3.5 release of Firefox as well as the latest 3.5.1 release.
The vulnerability, which comes about from the software's Unicode text handling system, allows a remote attacker to execute arbitrary code simply by embedding it into a web site: as soon as the visitor hits the affected page, the software crashes – leading to a denial of service attack – and under certain conditions the code will be executed by Windows.
With a simple exploit
already available, it's fair to say that if the ne'er-do-wells aren't already using this as an attack vector it won't take them long to wise up.
Are you starting to question just how much work was done checking the security of this latest Firefox branch or is the Mozilla Foundation just having a bad week? Share your thoughts over in the forums.