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FirefoxWeb browser · Mozilla

CVE-2023-4580

MEDIUM · 6.5 CVSS v3.1 Published 2023-09-11
Fix available
A fix is available. Upgrade to 115.2 / 117.0 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
Push notifications stored on disk in private browsing mode were not being encrypted potentially allowing the leak of sensitive information. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.

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

Push notifications stored on disk during private browsing mode were not encrypted, potentially exposing sensitive information contained in those notifications.

MitigationUpgrade to Firefox 117, Firefox ESR 115.2, Thunderbird 115.2 or later to ensure push notifications are properly encrypted in private browsing mode.

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:< 117.0
Firefox EsrWeb browser
Affected:< 115.2
ThunderbirdApplication
Affected:< 115.2

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
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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
    Open Firefox, go to Menu > Help > About Firefox (or navigate to about:support). Record the version number displayed.
    Affected if Version is below 117.0 (for regular Firefox) or below 115.2 (for Firefox ESR)
  2. Check installed Thunderbird version
    Open Thunderbird, go to Menu > Help > About Thunderbird. Record the version number displayed.
    Affected if Version is below 115.2
  3. Locate private browsing profile directory
    Navigate to the profile folder (about:profiles in Firefox, or check profile manager in Thunderbird). Identify profiles that have been used in Private Browsing mode.
    Affected if A private browsing profile exists and the application version is vulnerable
  4. Examine push notification storage
    In the private browsing profile folder, look for files in the push notification directory (typically under storage/default or notifications folder). Check if these files are encrypted or stored in plain text.
    Affected if Push notification files exist and are stored unencrypted (plain text JSON or readable content)
  5. Verify encryption status
    Open any found notification files in a text editor. If the content is readable (not garbled/encrypted), the notifications are unencrypted.
    Affected if Notification content is readable plain text rather than encrypted binary data

User is affected if running Firefox < 117.0 (or ESR < 115.2) or Thunderbird < 115.2, AND has used private browsing mode with push notifications enabled, with those notifications stored unencrypted on disk.

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 115.2 / 117.0 or later
Fixed in 115.2117.0
Interim mitigation

Upgrade to Firefox 117, Firefox ESR 115.2, Thunderbird 115.2 or later to ensure push notifications are properly encrypted in private browsing mode.

Recommended fix High confidence

Firefox 117.0+ | Firefox ESR 115.2+ | Thunderbird 115.2+ (depending on product in use)

  1. Check the current version of Mozilla product (Firefox, Firefox ESR, or Thunderbird) by navigating to Help > About in the application menu
  2. If using Firefox: upgrade to version 117.0 or later
  3. If using Firefox ESR: upgrade to version 115.2 or later
  4. If using Thunderbird: upgrade to version 115.2 or later
  5. Restart the application after upgrade
  6. Verify the installed version matches or exceeds the fixed release

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 / QA0.5 h
3.5 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-2023-4580 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