Mozilla developers and community identified 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.
In general these flaws cannot be exploited through email in the Thunderbird and Seamonkey products because scripting is disabled, but are potentially a risk in browser or browser-like contexts.
Benoit Jacob, Olli Pettay, Jan Varga, Jan de Mooij, Jesse Ruderman, Dan Gohman, and Christoph Diehl reported memory safety problems and crashes that affect Firefox ESR 24.3 and Firefox 27.
Gregor Wagner, Olli Pettay, Gary Kwong, Jesse Ruderman, Luke Wagner, Rob Fletcher, and Makoto Kato reported memory safety problems and crashes that affect Firefox 27.