Just one day after the Mozilla Foundation released Firefox 1.0, the group has revealed that prior versions of the open-source browser pose a security threat to users.
According to information released by Mozilla, multiple security holes have been plugged in all beta versions of Firefox to correct flaws that could lead to security bypass, exposure of sensitive data, privilege escalation and DoS (denial of service) attacks.
Research firm Secunia rates the vulnerabilities as "moderately critical" and recommended that users upgrade to Firefox 1.0.
Mozilla warned that successful exploits could also detect the presence of local files, spoof the file download dialog, or gain escalated privileges on vulnerable machines.
Details from a modified Bugzilla post show that Web sites that include images from local resources could be exploited to determine the existence of local images or cause a DoS by referencing certain devices.
Malicious hackers could potentially target Firefox users to steal passwords from Windows systems via file shares.
Another bug in the file download dialog box that truncates filenames was also corrected, Mozilla officials said. This could lead to scenarios where file extensions in the file download dialog are spoofed.
This is not the first time that potentially serious security holes have been flagged in the upstart browser. In July, Mozilla confirmed findings that its flagship browsers were vulnerable to attacks using the "shell:" scheme, which executes arbitrary code under Windows without the user having to click a link.
Still, open-source advocates arent too worried that Firefox growth will be slowed by security issues. "Most of these flaws, while real and theoretically exploitable, are not the sort of thing that will have IT administrators scrambling to address [them]. There will always be security flaws in Mozillas products, just like every other piece of software in existence," said Sean Mitchell, a Canadian developer who writes code for both IE and Firefox.
"From a security perspective, Firefoxs biggest advantage over IE is that it is not part of the core operating system, and therefore most of the security-related flaws will not be as critical as an integrated part of the OS," Mitchell said.