The lifecycle of IPC Actors allows managed actors to outlive their manager actors; and the former must ensure that they are not attempting to use a dead actor they have a reference to. Such a check was omitted in WebGL, resulting in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 84.
{ "binaries": [ { "binary_version": "84.0+build3-0ubuntu0.16.04.1", "binary_name": "firefox" }, { "binary_version": "84.0+build3-0ubuntu0.16.04.1", "binary_name": "firefox-dev" }, { "binary_version": "84.0+build3-0ubuntu0.16.04.1", "binary_name": "firefox-geckodriver" }, { "binary_version": "84.0+build3-0ubuntu0.16.04.1", "binary_name": "firefox-mozsymbols" } ], "availability": "No subscription required" }
{ "binaries": [ { "binary_version": "84.0+build3-0ubuntu0.18.04.1", "binary_name": "firefox" }, { "binary_version": "84.0+build3-0ubuntu0.18.04.1", "binary_name": "firefox-dev" }, { "binary_version": "84.0+build3-0ubuntu0.18.04.1", "binary_name": "firefox-geckodriver" }, { "binary_version": "84.0+build3-0ubuntu0.18.04.1", "binary_name": "firefox-mozsymbols" } ], "availability": "No subscription required" }
{ "binaries": [ { "binary_version": "84.0+build3-0ubuntu0.20.04.1", "binary_name": "firefox" }, { "binary_version": "84.0+build3-0ubuntu0.20.04.1", "binary_name": "firefox-dev" }, { "binary_version": "84.0+build3-0ubuntu0.20.04.1", "binary_name": "firefox-geckodriver" }, { "binary_version": "84.0+build3-0ubuntu0.20.04.1", "binary_name": "firefox-mozsymbols" } ], "availability": "No subscription required" }