dbcve.org
FirefoxWeb browser · Mozilla

CVE-2023-25751

MEDIUM · 6.5 CVSS v3.1 Published 2023-06-02
Fix available
A fix is available. Upgrade to 102.9 / 111.0 or later.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable No privileges

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 · unedited
Sometimes, when invalidating JIT code while following an iterator, the newly generated code could be overwritten incorrectly. This could lead to a potentially exploitable crash. This vulnerability affects Firefox < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.

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 confidence

A race condition in Firefox's SpiderMonkey JIT compiler allows newly generated JIT code to be incorrectly overwritten when invalidating JIT code while following an iterator. This memory corruption during JIT code management can lead to a potentially exploitable crash.

MitigationUpgrade to Firefox 111, Firefox ESR 102.9, or Thunderbird 102.9 or later to patch the JIT code invalidation vulnerability.

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
Affected:< 111.0
Firefox EsrWeb browser
Affected:< 102.9
ThunderbirdApplication
Affected:< 102.9

CVSS 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
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Mozilla product
    Check which application is installed: Firefox, Firefox ESR, or Thunderbird. In Windows, look in Program Files or the application icon. On Linux, check the package name (firefox, firefox-esr, thunderbird). On macOS, check /Applications for Firefox.app or Thunderbird.app.
    Affected if The product is Firefox, Firefox ESR, or Thunderbird - any of these three are affected by this CVE.
  2. Determine the installed version number
    For Firefox: Enter 'about:support' in the address bar and look at the 'Version' field. For Thunderbird: Enter 'about:support' and check the version. On command line: 'firefox --version', 'thunderbird --version', or check the package manager (dpkg -r, rpm -q, etc.).
    Affected if The version is below 111.0 for Firefox, below 102.9 for Firefox ESR, or below 102.9 for Thunderbird.
  3. Verify if SpiderMonkey JIT is enabled
    In Firefox address bar, enter 'about:config' and search for 'jit'. Check if javascript.options.jit' is set to true. Also check 'javascript.options.baselinejit' and 'javascript.options.ion' - these control JIT compilation. For Thunderbird, the same about:config method applies.
    Affected if JIT is enabled (any of the jit-related options set to true). The vulnerability only affects environments where JIT compilation is active.
  4. Confirm application is actively used with JIT code generation
    This is implicit - if the browser or Thunderbird is used to visit websites or process content that triggers JavaScript execution, the JIT compiler generates code. The vulnerability occurs during JIT code invalidation while following an iterator, which happens during normal JavaScript execution in web content.
    Affected if The application has been used to browse websites or process content containing JavaScript, which triggers JIT code generation.

You are affected if you have Firefox below 111.0, Firefox ESR below 102.9, or Thunderbird below 102.9, and JIT compilation is enabled (the default state), and you use the browser to process JavaScript content.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 102.9 / 111.0 or later
Fixed in 102.9111.0
Interim mitigation

Upgrade to Firefox 111, Firefox ESR 102.9, or Thunderbird 102.9 or later to patch the JIT code invalidation vulnerability.

Recommended fix High confidence

Firefox 111.0, Firefox ESR 102.9, Thunderbird 102.9

  1. 1. Back up any important data and bookmarks in your current Firefox, Firefox ESR, or Thunderbird installation
  2. 2. Close all instances of the affected application
  3. 3. Download the latest version from the official Mozilla website (www.mozilla.org) or use your system's package manager
  4. 4. For Firefox: Install version 111.0 or later
  5. 5. For Firefox ESR: Install version 102.9 or later
  6. 6. For Thunderbird: Install version 102.9 or later
  7. 7. Restart the application after installation
  8. 8. Verify the installed version by checking Help > About (Firefox/Thunderbird)

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firefox Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,920.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-25751 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-25751 in production — separate from our analysis above.

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.

What this is

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.

What belongs here
  • 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