FirefoxWeb browser · Mozilla
CVE-2024-29943
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn attacker was able to perform an out-of-bounds read or write on a JavaScript object by fooling range-based bounds check elimination. This vulnerability affects Firefox < 124.0.1.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA vulnerability in Firefox's JavaScript engine allows attackers to bypass range-based bounds check elimination, enabling out-of-bounds read/write operations on JavaScript objects. This memory corruption issue in the browser's just-in-time (JIT) compilation optimization can lead to remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FirefoxWeb browser
< 124.0.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check if Firefox is installedOn Windows, check HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox in the registry or look in C:\Program Files\Mozilla Firefox. On Linux, run 'which firefox' or check package manager listings. On Mac, check /Applications/Firefox.app.Affected if Firefox is not found in the system - not affected if no Firefox installed
-
Determine installed Firefox versionOpen Firefox and navigate to about:firefox, or from command line run 'firefox --version' (Linux/Mac) or check the registry key InstallPath\Uninstall\DisplayVersion (Windows).Affected if Cannot determine version - verification incomplete
-
Compare version against 124.0.1Parse the version number from step 2 and compare it to 124.0.1. Ensure the full version string is compared (e.g., 124.0, 124.0.0, 123.0.1 all count as below 124.0.1).Affected if Version is 124.0 or lower (e.g., 124.0, 123.0.1, 122.0) - the environment is affected and vulnerable to exploitation
If Firefox is installed and the version is less than 124.0.1, the environment is vulnerable to this JIT bounds check elimination bypass and potential remote code execution.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped124.0.1
Update Firefox to version 124.0.1 or later. Apply patch management procedures to ensure all affected browser instances are updated across the organization.
Firefox 124.0.1 or later
- Open Firefox and navigate to Help > About Firefox (or go to about:support)
- Click 'Check for Updates' or wait for the automatic update prompt
- Ensure the installed version is 124.0.1 or later
- If automatic update is unavailable, download Firefox 124.0.1 or later from the official Mozilla website (www.mozilla.org)
- Restart the browser after updating
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-29943 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-29943 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data