Firefox ESR vulnerabilities
167 known vulnerabilities in Firefox ESR from Mozilla. 167 are rated high or critical, and 9 have been exploited in real attacks. Each entry lists the affected versions and the release that fixes it, where the vendor has published one.
Latest first
- 8.1 High severity
Firefox: Origin Validation Error
A same-origin policy violation could have allowed the theft of cross-origin URL entries, leaking the result of a redirect, via `performance.getEntries()`. This vulnerability affects Firefox < 106, Firefox ESR < 102.4, and Thunderbird < 102.4.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Mozilla developers Nika Layzell, Timothy Nikkel, Sebastian Hengst, Andreas Pehrson, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 104 and Firefox ESR 102.2. Some of these bugs showed evidence of memory corruption and we presume th
- 8.8 High severity
Thunderbird: Out-of-bounds Write
Members the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 103, Firefox ESR 102.1, and Firefox ESR 91.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploite
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Mozilla developer Nika Layzell and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 103 and Firefox ESR 102.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been e
- 7.5 High severity
Firefox ESR: Use After Free
A data race could occur in the <code>PK11_ChangePW</code> function, potentially leading to a use-after-free vulnerability. In Firefox, this lock protected the data when a user changed their master password. This vulnerability affects Firefox ESR < 102.2 and Th
- 8.8 High severity
Thunderbird: Improper Preservation of Permissions
A cross-origin iframe referencing an XSLT document would inherit the parent domain's permissions (such as microphone or camera access). This vulnerability affects Thunderbird < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox <
- 7.5 High severity
Firefox ESR: Improper Restriction of Rendered UI Layers or Frames
When combining CSS properties for overflow and transform, the mouse cursor could interact with different coordinates than displayed. This vulnerability affects Firefox ESR < 102.1, Firefox ESR < 91.12, Firefox < 103, Thunderbird < 102.1, and Thunderbird < 91.1
- 8.8 High severity
Firefox: Use After Free
The Mozilla Fuzzing Team reported potential vulnerabilities present in Thunderbird 91.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnera
- 8.8 High severity
Firefox: Integer Overflow or Wraparound
In the <code>nsTArray_Impl::ReplaceElementsAt()</code> function, an integer overflow could have occurred when the number of elements to replace was too large for the container. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, a
- 9.8 Critical severity
Firefox: Use After Free
Session history navigations may have led to a use-after-free and potentially exploitable crash. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.
- 8.8 High severity
Firefox: Inclusion of Functionality from Untrusted Control Sphere
An iframe that was not permitted to run scripts could do so if the user clicked on a <code>javascript:</code> link. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.
- 9.8 Critical severity
Thunderbird: Out-of-bounds Read
Mozilla developers Andrew McCreight, Nicolas B. Pierron, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 100 and Firefox ESR 91.9. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some o
- 8.8 High severity
Thunderbird: Use of Uninitialized Resource
A crafted CMS message could have been processed incorrectly, leading to an invalid memory read, and potentially further memory corruption. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.
- 8.8 High severity
Thunderbird: Improper Restriction of Operations within the Bounds of a Memory Buffer
On arm64, WASM code could have resulted in incorrect assembly generation leading to a register allocation problem, and a potentially exploitable crash. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.
- 8.8 High severity
Thunderbird: External Control of File Name or Path
When downloading files on Windows, the % character was not escaped, which could have lead to a download incorrectly being saved to attacker-influenced paths that used variables such as %HOMEPATH% or %APPDATA%.<br>*This bug only affects Firefox for Windows. Oth
- 9.8 Critical severity
Thunderbird: Out-of-bounds Write
A malicious webpage could have caused an out-of-bounds write in WebGL, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.
- 9.8 Critical severity
Thunderbird: Permissive Cross-domain Security Policy with Untrusted Domains
A malicious website could have learned the size of a cross-origin resource that supported Range requests. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Mozilla developers and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 102. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. Th
- 8.8 High severity
Firefox: Improperly Controlled Modification of Object Prototype Attributes
If an object prototype was corrupted by an attacker, they would have been able to set undesired attributes on a JavaScript object, leading to privileged code execution. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thund
- 9.8 Critical severity
Thunderbird: Out-of-bounds Write
Mozilla developers Andrew McCreight, Gabriele Svelto, Tom Ritter and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 99 and Firefox ESR 91.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort
- 8.8 High severity
Thunderbird: Incorrect Default Permissions
Documents in deeply-nested cross-origin browsing contexts could have obtained permissions granted to the top-level origin, bypassing the existing prompt and wrongfully inheriting the top-level permissions. This vulnerability affects Thunderbird < 91.9, Firefox
- 8.8 High severity
Thunderbird: Out-of-bounds Write
Mozilla developers and community members Nika Layzell, Andrew McCreight, Gabriele Svelto, and the Mozilla Fuzzing Team reported memory safety bugs present in Thunderbird 91.7. Some of these bugs showed evidence of memory corruption and we presume that with eno
- 8.8 High severity
Thunderbird: Out-of-bounds Write
If a compromised content process sent an unexpected number of WebAuthN Extensions in a Register command to the parent process, an out of bounds write would have occurred leading to memory corruption and a potentially exploitable crash. This vulnerability affec
- 9.6 Critical severity
Mozilla Firefox Use-After-Free Exploited
An unexpected message in the WebGPU IPC framework could lead to a use-after-free and exploitable sandbox escape. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Androi
- 8.8 High severity
Mozilla Firefox Use-After-Free Exploited
Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunde
- 7.5 High severity
Firefox: Time-of-check Time-of-use (TOCTOU) Race Condition
When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98,
- 9.6 Critical severity
Firefox: Protection Mechanism Failure
If an attacker could control the contents of an iframe sandboxed with <code>allow-popups</code> but not <code>allow-scripts</code>, they were able to craft a link that, when clicked, would lead to JavaScript execution in violation of the sandbox. This vulnerab
- 8.8 High severity
Firefox: Use After Free
An attacker could have caused a use-after-free by forcing a text reflow in an SVG object leading to a potentially exploitable crash. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
- 8.8 High severity
Firefox: Out-of-bounds Write
Mozilla developers Paul Adenot and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 96 and Firefox ESR 91.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exp
- 8.8 High severity
Firefox: Concurrent Execution using Shared Resource with Improper Synchronization
When a worker is shutdown, it was possible to cause script to run late in the lifecycle, at a point after where it should not be possible. This vulnerability affects Firefox < 96, Thunderbird < 91.6, and Firefox ESR < 91.6.
- 8.8 High severity
Firefox: Protection Mechanism Failure
Web-accessible extension pages (pages with a moz-extension:// scheme) were not correctly enforcing the frame-ancestors directive when it was used in the Web Extension's Content Security Policy. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and F
- 9.6 Critical severity
Firefox: Protection Mechanism Failure
If a document created a sandboxed iframe without <code>allow-scripts</code>, and subsequently appended an element to the iframe's document that e.g. had a JavaScript event handler - the event handler would have run despite the iframe's sandbox. This vulnerabil
- 8.8 High severity
Firefox: Improper Control of Generation of Code
If a user was convinced to drag and drop an image to their desktop or other folder, the resulting object could have been changed into an executable script which would have run arbitrary code after the user clicked on it. This vulnerability affects Firefox < 97
- 7.1 High severity
Firefox: Time-of-check Time-of-use (TOCTOU) Race Condition
A Time-of-Check Time-of-Use bug existed in the Maintenance (Updater) Service that could be abused to grant Users write access to an arbitrary directory. This could have been used to escalate to SYSTEM access.<br>*This bug only affects Firefox on Windows. Other
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Mozilla developers Calixte Denizet, Kershaw Chang, Christian Holler, Jason Kratzer, Gabriele Svelto, Tyson Smith, Simon Giesecke, and Steve Fink reported memory safety bugs present in Firefox 95 and Firefox ESR 91.4. Some of these bugs showed evidence of memor
- 8.8 High severity
Firefox ESR: Improper Encoding or Escaping of Output
The constructed curl command from the "Copy as curl" feature in DevTools was not properly escaped for PowerShell. This could have lead to command injection if pasted into a Powershell prompt.<br>*This bug only affects Thunderbird for Windows. Other operating s
- 8.8 High severity
Firefox ESR: Use After Free
Certain network request objects were freed too early when releasing a network request handle. This could have lead to a use-after-free causing a potentially exploitable crash. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
- 8.8 High severity
Firefox ESR: Out-of-bounds Write
Applying a CSS filter effect could have accessed out of bounds memory. This could have lead to a heap-buffer-overflow causing a potentially exploitable crash. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
- 7.5 High severity
Firefox ESR: Concurrent Execution using Shared Resource with Improper Synchronization
Constructing audio sinks could have lead to a race condition when playing audio files and closing windows. This could have lead to a use-after-free causing a potentially exploitable crash. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunde
- 8.8 High severity
Firefox ESR: Improperly Controlled Modification of Object Prototype Attributes
If an attacker was able to corrupt the methods of an Array object in JavaScript via prototype pollution, they could have achieved execution of attacker-controlled JavaScript code in a privileged context. This vulnerability affects Firefox ESR < 91.9.1, Firefox