Mozilla developers and community members reported memory safety bugs present in Firefox 69 and Firefox ESR 68.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters - enabling the use of entities to mask the actual characters of interest from filters. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

If two same-origin documents set document.domain differently to become cross-origin, it was possible for them to call arbitrary DOM methods/getters/setters on the now-cross-origin window. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

By using a form with a data URI it was possible to gain access to the privileged JSONView object that had been cloned into content. Impact from exposing this object appears to be minimal, however it was a bypass of existing defense in depth mechanisms. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

A fixed-size stack buffer could overflow in nrappkit when doing WebRTC signaling. This resulted in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Mozilla community member Philipp reported a memory safety bug present in Firefox 68 when 360 Total Security was installed. This bug showed evidence of memory corruption in the accessibility engine and we presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Firefox < 69, Thunderbird < 68.2, and Firefox ESR < 68.2.

When following the value's prototype chain, it was possible to retain a reference to a locale, delete it, and subsequently reference it. This resulted in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Improper refcounting of soft token session objects could cause a use-after-free and crash (likely limited to a denial of service). This vulnerability affects Firefox < 71.

When encrypting with a block cipher, if a call to NSC_EncryptUpdate was made with data smaller than the block size, a small out of bounds write could occur. This could have caused heap corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla Firefox 20.0a1 and earlier allows remote attackers to cause a denial of service (crash), related to event handling with frames.

When the pointer lock is enabled by a website though requestPointerLock(), no user notification is given. This could allow a malicious website to hijack the mouse pointer and confuse users. This vulnerability affects Firefox < 69.0.1.

The Firefox installer allows Firefox to be installed to a custom user writable location, leaving it unprotected from manipulation by unprivileged users or malware. If the Mozilla Maintenance Service is manipulated to update this unprotected location and the updated maintenance service in the unprotected location has been altered, the altered maintenance service can run with elevated privileges during the update process due to a lack of integrity checks. This allows for privilege escalation if the executable has been replaced locally. <br>*Note: This attack requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Firefox < 69, Firefox ESR < 60.9, and Firefox ESR < 68.1.

It is possible to delete an IndexedDB key value and subsequently try to extract it during conversion. This results in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.

Logging-related command line parameters are not properly sanitized when Firefox is launched by another program, such as when a user clicks on malicious links in a chat application. This can be used to write a log file to an arbitrary location such as the Windows 'Startup' folder. <br>*Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

A type confusion vulnerability exists in Spidermonkey, which results in a non-exploitable crash. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

A vulnerability exists in WebRTC where malicious web content can use probing techniques on the getUserMedia API using constraints to reveal device properties of cameras on the system without triggering a user prompt or notification. This allows for the potential fingerprinting of users. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

WebRTC in Firefox will honor persisted permissions given to sites for access to microphone and camera resources even when in a third-party context. In light of recent high profile vulnerabilities in other software, a decision was made to no longer persist these permissions. This avoids the possibility of trusted WebRTC resources being invisibly embedded in web content and abusing permissions previously given by users. Users will now be prompted for permissions on each use. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

The "Forget about this site" feature in the History pane is intended to remove all saved user data that indicates a user has visited a site. This includes removing any HTTP Strict Transport Security (HSTS) settings received from sites that use it. Due to a bug, sites on the pre-load list also have their HSTS setting removed. On the next visit to that site if the user specifies an http: URL rather than secure https: they will not be protected by the pre-loaded HSTS setting. After that visit the site's HSTS setting will be restored. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

A use-after-free vulnerability can occur while manipulating video elements if the body is freed while still in use. This results in a potentially exploitable crash. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.