dbcve.org
FirefoxWeb browser · Mozilla

CVE-2023-25742

MEDIUM · 6.5 CVSS v3.1 Published 2023-06-02
Fix available
A fix is available. Upgrade to 102.8 / 110.0 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
When importing a SPKI RSA public key as ECDSA P-256, the key would be handled incorrectly causing the tab to crash. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

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

This is a type confusion vulnerability where importing a SPKI-formatted RSA public key while specifying ECDSA P-256 as the algorithm causes incorrect key handling, leading to a tab crash (denial of service). The browser incorrectly processes the RSA key structure as if it were an ECDSA P-256 key.

MitigationUpgrade to Firefox 110 or later, Thunderbird 102.8 or later, or Firefox ESR 102.8 or later to resolve 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:< 110.0
Firefox EsrWeb browser
Affected:< 102.8
ThunderbirdApplication
Affected:< 102.8

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. Check Firefox version
    Open Firefox, go to Menu > Help > About Firefox (or navigate to about:support). Locate the 'Version' field.
    Affected if The version number displayed is below 110.0 (for regular Firefox) or below 102.8 (for Firefox ESR).
  2. Check Thunderbird version
    Open Thunderbird, go to Menu > Help > About Thunderbird. Locate the 'Version' field.
    Affected if The version number displayed is below 102.8.
  3. Identify WebCrypto usage
    Review web application code or browser extension JavaScript for calls to the Web Crypto API, specifically the 'importKey' method with parameters that specify 'ECDSA' algorithm while importing RSA key data.
    Affected if Code uses crypto.subtle.importKey with 'spki' format, RSA key data, and 'ECDSA' algorithm with namedCurve 'P-256'.
  4. Test for crash condition
    Create a test page that calls crypto.subtle.importKey('spki', rsaPublicKeySpkiBuffer, {name: 'ECDSA', namedCurve: 'P-256'}, true, []). Monitor if the tab crashes.
    Affected if The importKey call succeeds and triggers a tab crash, indicating the type confusion is present.

A user is affected if they are running Firefox below 110.0, Firefox ESR below 102.8, or Thunderbird below 102.8 AND encounter specifically crafted WebCrypto importKey calls that attempt to import an RSA key as ECDSA P-256.

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 102.8 / 110.0 or later
Fixed in 102.8110.0
Interim mitigation

Upgrade to Firefox 110 or later, Thunderbird 102.8 or later, or Firefox ESR 102.8 or later to resolve this vulnerability.

Recommended fix High confidence

Firefox 110.0, Firefox ESR 102.8, or Thunderbird 102.8

  1. 1. Identify the Mozilla product needing update (Firefox, Firefox ESR, or Thunderbird)
  2. 2. Check the current version by navigating to Help > About in the application menu
  3. 3. If running Firefox < 110.0, Firefox ESR < 102.8, or Thunderbird < 102.8, download and install the corresponding fixed version from the official Mozilla website
  4. 4. Restart the application after installing the update

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
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

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-2023-25742 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