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FirefoxWeb browser · Mozilla

CVE-2022-38478

HIGH · 8.8 CVSS v3.1 Published 2022-12-22
Fix available
A fix is available. Upgrade to 91.13 / 102.2 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
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 exploited to run arbitrary code. This vulnerability affects Thunderbird < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox < 104.

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

Memory safety bugs in Firefox and Thunderbird (including potential buffer overflows or use-after-free conditions) that could allow memory corruption and potentially arbitrary code execution. The vulnerabilities were discovered through fuzzing and affect multiple versions prior to the fixes.

MitigationApply vendor-supplied updates: upgrade Firefox to version 104 or later, Firefox ESR to 91.13/102.2 or later, and Thunderbird to 102.2 or later (or 91.13 for older ESR branches).

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:< 104.0>= 102.0, < 102.2
Firefox EsrWeb browser
Affected:< 91.13
ThunderbirdApplication
Affected:< 91.13>= 102.0, < 102.2

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. Identify installed Mozilla product
    Check for installed Firefox or Thunderbird: On Windows, look in C:\Program Files\Mozilla Firefox or C:\Program Files\Mozilla Thunderbird. On macOS, check /Applications/Firefox.app or /Applications/Thunderbird.app. On Linux, run 'dpkg -l | grep -i firefox' or 'rpm -qa | grep -i thunderbird'.
    Affected if The system has Firefox or Thunderbird installed
  2. Determine installed version
    On Windows, open Help > About Firefox/Thunderbird, or check the version in the Windows Registry under HKLM\SOFTWARE\Mozilla\Mozilla Firefox or HKLM\SOFTWARE\Mozilla\Thunderbird. On macOS, right-click the app in Applications and select Get Info, or run '/Applications/Firefox.app/Contents/MacOS/firefox --version'. On Linux, run 'firefox --version' or 'thunderbird --version'.
    Affected if Unable to determine version - assume potentially affected if product is present
  3. Compare Firefox version against affected range
    If Firefox is installed, note its version. Affected versions are: any version < 104.0, OR versions 102.0 through 102.1.x. This means versions 103.x, 102.x (below 102.2), 101.x, 100.x and earlier are all affected.
    Affected if Installed Firefox version is less than 104.0, or is 102.0-102.1.x (any 102.0.x or 102.1.x version)
  4. Compare Firefox ESR version against affected range
    If Firefox ESR is installed, note its version (check Help > About for ESR version). Affected versions are any version < 91.13. This includes ESR 91.12 and earlier, as well as older ESR branches like 78.x, 68.x, etc.
    Affected if Installed Firefox ESR version is less than 91.13
  5. Compare Thunderbird version against affected range
    If Thunderbird is installed, note its version. Affected versions are: any version < 91.13, OR versions 102.0 through 102.1.x. This means versions 91.12 and below, as well as 102.0.x and 102.1.x, are affected.
    Affected if Installed Thunderbird version is less than 91.13, or is 102.0-102.1.x (any 102.0.x or 102.1.x version)

The environment is affected if any installed Mozilla product (Firefox, Firefox ESR, or Thunderbird) matches the affected version ranges: Firefox < 104.0 or 102.0-102.1.x, Firefox ESR < 91.13, or Thunderbird < 91.13 or 102.0-102.1.x.

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 91.13 / 102.2 / 104.0 or later
Fixed in 91.13102.2104.0
Interim mitigation

Apply vendor-supplied updates: upgrade Firefox to version 104 or later, Firefox ESR to 91.13/102.2 or later, and Thunderbird to 102.2 or later (or 91.13 for older ESR branches).

Recommended fix High confidence

Firefox 104.0+, Firefox ESR 91.13+, Firefox ESR 102.2+, Thunderbird 91.13+, or Thunderbird 102.2+ (depending on your release track)

  1. Identify the currently installed Firefox, Firefox ESR, or Thunderbird version via Help > About (or 'firefox --version' / 'thunderbird --version' command line)
  2. If running Firefox (non-ESR) between 102.0 and 102.1.x: upgrade to Firefox 104.0 or later
  3. If running Firefox ESR 91.x: upgrade to Firefox ESR 91.13 or later
  4. If running Firefox ESR 102.x: upgrade to Firefox ESR 102.2 or later
  5. If running Thunderbird 91.x: upgrade to Thunderbird 91.13 or later
  6. If running Thunderbird 102.x: upgrade to Thunderbird 102.2 or later
  7. Restart the application after upgrade and verify the new version in Help > About
Caveat Standard Mozilla releases typically maintain backward compatibility; minor add-on incompatibilities may occur between major version jumps

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
6.0 hours of engineering $1,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

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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-2022-38478 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