Use-after-free vulnerability in DirectionalityUtils.cpp in Mozilla Firefox before 33.0, Firefox ESR 31.x before 31.2, and Thunderbird 31.x before 31.2 allows remote attackers to execute arbitrary code via text that is improperly handled during the interaction between directionality resolution and layout.

The get_tile function in Mozilla Firefox before 33.0, Firefox ESR 31.x before 31.2, and Thunderbird 31.x before 31.2 allows remote attackers to cause a denial of service (out-of-bounds write and application crash) or possibly execute arbitrary code via WebM frames with invalid tile sizes that are improperly handled in buffering operations during video playback.