Mozilla released Firefox 31 Tuesday and the new update fixes 11 vulnerabilities.
Three of the flaws in the browser are critical, which indicates they can end up exploited to execute code and install software without requiring user interaction beyond normal browsing.
Various memory safety hazards fixed in Firefox 31 also fall under the critical category.
“Mozilla developers and community identified and fixed several memory safety bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these bugs showed evidence of memory corruption under certain circumstances, and we presume that with enough effort at least some of these could be exploited to run arbitrary code,” Mozilla said in its advisory.
Three of the five high-impact vulnerabilities addressed in the latest version of the Web browser are use-after-free issues that result in a potentially exploitable crash. The crashes occur when certificates end up manipulated in a certain way in the trusted cache, when the FireOnStateChange event triggers in some circumstances, and when control messages for Web Audio are ordered and processed incorrectly.
A different potentially exploitable crash occurs in the Skia library when scaling high quality images and the scaling operation takes too long. The last high-impact vulnerability is a buffer overflow during Web Audio buffering for playback, which can end up exploited with specially crafted audio content. Atte Kettunen from OUSPG, Jethro Beekman of the University of California, Tyson Smith, Jesse Schwartzentruber and a Mozilla community member named John found the high-impact bugs.
There were also some moderate-impact bugs, such as what Mozilla called “IFRAME sandbox same-origin access through redirect” and “certificate parsing broken by non-standard character encoding.” The flaws came to Mozilla developer Boris Zbarsky and Mozilla security researcher Christian Holler.
All of these vulnerabilities affect Thunderbird as well. Mozilla addressed the security holes in the email client with the release of Thunderbird 31.