dbcve.org
FirefoxWeb browser · Mozilla

CVE-2023-25731

HIGH · 8.8 CVSS v3.1 Published 2023-06-02
Fix available
A fix is available. Upgrade to 110.0 or later.
See remediation →
95/100
Remediation priority · Urgent
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
Due to URL previews in the network panel of developer tools improperly storing URLs, query parameters could potentially be used to overwrite global objects in privileged code. 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 confidence

In Firefox versions prior to 110, the developer tools network panel's URL preview feature improperly stores URLs, allowing maliciously crafted query parameters to overwrite global objects in privileged code contexts. This constitutes a prototype pollution vulnerability enabling code execution in privileged contexts.

MitigationUpgrade Firefox to version 110 or later. For enterprise environments, deploy the browser update via standard software distribution mechanisms and verify completion across affected workstations.

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:< 110.0

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 checks

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

  1. Determine installed Firefox version
    Navigate to Menu > Help > About Firefox, or enter 'about:support' in the address bar, or run 'firefox --version' from command line
    Affected if The displayed version is less than 110.0 (for example, 109.0, 108.0, etc.)
  2. Check Firefox policy configuration for developer tools
    Open 'about:config' and search for 'devtools.policy' or check for enterprise policy files in the installation directory
    Affected if Developer tools are not restricted by policy and the browser version is below 110.0
  3. Review active browser extensions
    Navigate to 'about:addons' and examine installed extensions, or check the extensions folder in the Firefox profile directory
    Affected if The browser version is below 110.0 and extensions with broad permissions are installed (this increases exploitability but is not a requirement)
  4. Verify network request logging status
    Open Developer Tools (F12 or Ctrl+Shift+I), click the Network tab, and attempt to load a URL with a query parameter like '?__proto__=test'
    Affected if The URL preview displays the parameter without sanitization and the Firefox version is below 110.0

The environment is affected if Mozilla Firefox version 110.0 or later is not installed, regardless of developer tools usage since the vulnerable code exists in the browser binary.

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 110.0 or later
Fixed in 110.0
Interim mitigation

Upgrade Firefox to version 110 or later. For enterprise environments, deploy the browser update via standard software distribution mechanisms and verify completion across affected workstations.

Recommended fix High confidence

Firefox 110.0 or later

  1. Back up Firefox profile data (bookmarks, saved logins, preferences) to preserve user data
  2. Open Firefox and navigate to Menu > Help > About Firefox to check the current version
  3. If version is below 110.0, Firefox will typically auto-update; wait for the update to download and install
  4. Alternatively, download Firefox 110.0 or later from the official Mozilla website (www.mozilla.org)
  5. Run the installer and complete the installation process
  6. Restart Firefox if not prompted to do so automatically
  7. Verify the update by checking Menu > Help > About Firefox shows version 110.0 or higher
Caveat Minor browser upgrades typically have minimal breaking changes; however, some older extensions or add-ons may require updates for compatibility with Firefox 110+

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

Fix this in Firefox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

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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-2023-25731 in production — separate from our analysis above.

No notes yet

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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