Mozilla developers identified and fixed several stability bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these crashes 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. This MFSA addresses several CVEs; all but one are specific to Firefox 3.6. Bob Clary and Carsten Book reported crashes in the browser engine which affected all supported versions of the browser engine. (CVE-2010-0167) Upstream advisory: http://www.mozilla.org/security/announce/2010/mfsa2010-11.html This was fixed in upstream Firefox 3.0.18, and via RHSA-2010:0112 in Red Hat Enterprise Linux 4 and 5. https://rhn.redhat.com/errata/RHSA-2010-0112.html
This issue only affects Thunderbird and Seamonkey builds based on Gecko 1.9. The Thunderbird and Seamonkey versions as provided with Red Hat Enterprise Linux 3, 4, and 5 are based on Gecko 1.8, so they are not vulnerable to this issue.