dbcve.org
FirefoxWeb browser · Mozilla

CVE-2022-31738

MEDIUM · 6.5 CVSS v3.1 Published 2022-12-22
Fix available
A fix is available. Upgrade to 91.10 / 101 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
When exiting fullscreen mode, an iframe could have confused the browser about the current state of fullscreen, resulting in potential user confusion or spoofing attacks. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

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 vulnerability in Firefox, Firefox ESR, and Thunderbird allows an iframe to confuse the browser about its fullscreen state when exiting fullscreen mode. This state confusion could enable spoofing attacks where users believe they are interacting with one context while actually seeing another.

MitigationUpdate to Firefox 101, Firefox ESR 91.10, Thunderbird 91.10, or later versions to remediate this 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:< 101
Firefox EsrWeb browser
Affected:< 91.10
ThunderbirdApplication
Affected:< 91.10

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
High
Availability
None

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

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. Check installed Firefox version
    In Firefox, go to Menu > Help > About Firefox, or navigate to about:support in the address bar. The version number is displayed at the top of the page.
    Affected if The version displayed is below 101 (for example, 100.x, 99.x, etc.)
  2. Check installed Firefox ESR version
    In Firefox ESR, go to Menu > Help > About Firefox, or navigate to about:support. The version will include 'ESR' designation (for example, 91.9.x ESR).
    Affected if The version displayed is below 91.10 (for example, 91.9.x ESR, 91.8.x ESR, etc.)
  3. Check installed Thunderbird version
    In Thunderbird, go to Menu > Help > About Thunderbird, or navigate to about:support. The version number is displayed at the top.
    Affected if The version displayed is below 91.10 (for example, 91.9.x, 91.8.x, etc.)
  4. Compare version against affected ranges
    If using an older installation or an enterprise deployment, verify the exact version number matches the affected ranges: Firefox < 101, Firefox ESR < 91.10, Thunderbird < 91.10.
    Affected if The installed version number falls below the specified thresholds for any of these products.

You are affected if any installed Mozilla product (Firefox, Firefox ESR, or Thunderbird) has a version number below the corresponding threshold (101, 91.10, or 91.10 respectively).

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 91.10 / 101 or later
Fixed in 91.10101
Interim mitigation

Update to Firefox 101, Firefox ESR 91.10, Thunderbird 91.10, or later versions to remediate this vulnerability.

Recommended fix High confidence

Firefox 101+, Firefox ESR 91.10+, Thunderbird 91.10+

  1. 1. Determine which Mozilla product is affected (Firefox, Firefox ESR, or Thunderbird)
  2. 2. For Firefox: Upgrade to version 101 or later
  3. 3. For Firefox ESR: Upgrade to version 91.10 or later
  4. 4. For Thunderbird: Upgrade to version 91.10 or later
  5. 5. Restart the application after upgrading
  6. 6. Verify the version by checking Help > About (or equivalent) to confirm the installed version meets the minimum fixed version

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

Fix this in Firefox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-31738 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2022-31738 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