FirefoxWeb browser · Mozilla
CVE-2023-25733
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 · uneditedThe return value from `gfx::SourceSurfaceSkia::Map()` wasn't being verified which could have potentially lead to a null pointer dereference. This vulnerability affects Firefox < 110.
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 confidenceIn Firefox versions prior to 110, the return value from `gfx::SourceSurfaceSkia::Map()` was not being verified. This missing check could lead to a null pointer dereference when the function fails to return a valid surface mapping, potentially causing a denial of service or unexpected behavior.
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
< 110.0CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 checksWork through these to decide whether this CVE applies to you.
-
Check if Firefox is installedOn Windows, look for firefox.exe in Program Files or Program Files (x86). On macOS, check /Applications for Firefox.app. On Linux, run 'which firefox' or check /usr/lib/firefox or /opt/firefox.Affected if Firefox is not found on the system, this CVE does not apply
-
Determine the installed Firefox versionWindows: Right-click firefox.exe > Properties > Details tab > File version. macOS: Right-click Firefox.app > Get Info > Version. Linux: Run 'firefox --version' in terminal or check package via 'dpkg -l firefox' or 'rpm -q firefox'.Affected if Unable to determine version, cannot assess impact
-
Compare installed version against affected rangeCompare the version number found to 110.0. For example, if version shows 109.0 or 109.0.1, it is before 110.0. Note that some systems may show extended version strings - focus on the main version number.Affected if Installed version is 109.x or any version below 110.0 (e.g., 108.x, 107.x, etc.)
If Firefox is installed and its version is less than 110.0, the environment is affected by this CVE.
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 · scoped110.0
Update Firefox to version 110 or later to receive the patch that properly validates the return value from `gfx::SourceSurfaceSkia::Map()`.
Firefox 110.0
- Open Firefox and navigate to the Help menu (three horizontal lines in the top right)
- Select 'About Firefox' from the dropdown menu
- Firefox will automatically check for and download the latest update
- Once the download completes, click 'Restart to update Firefox'
- After restart, verify the version by going to Help > About Firefox - it should show 110.0 or later
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-25733 — 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-2023-25733 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