Risk: Medium
Mozilla and Firefox users have been warned of a number of potentially troublesome security vulnerabilities within their software.
The most serious flaw involves a buffer overflow bug in the way Mozilla processes the NNTP (news) protocol. The bug creates a means for hackers to inject hostile code into vulnerable systems, providing they trick users into following maliciously constructed news server links. All versions of Mozilla prior to 1.7.5 are affected. Firefox users are advised to make sure they are running version 1.0 to minimise any risk. The flaw was discovered by Polish firm iSEC Security Research.
Secunia has also discovered a flaw that creates a means to spoof the source displayed in the Firefox's download dialog box. The vulnerability has been confirmed in Mozilla 1.7.3 for Linux, Mozilla 1.7.5 for Windows, and Mozilla Firefox 1.0. Other versions may also be affected. It advises Firefox users to avoid download links from untrusted sources pending the availability of patches from the Mozilla project.
Finally, there's a less serious problem affecting Firefox and its email client Thunderbird. Security researchers have found that temporary files are stored by the popular packages in a format that makes it possible for snoops to read the content of downloads and attachments of other users on the same machine.
An overview of these flaws and suggested workarounds has been published to the popular SecurityFocus web site.