FirefoxWeb browser · Mozilla
CVE-2020-6815
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 · uneditedMozilla developers reported memory safety and script safety bugs present in Firefox 73. Some of these bugs showed evidence of memory corruption or escalation of privilege and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 74.
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 · moderate confidenceMemory safety and script safety vulnerabilities in Mozilla Firefox versions prior to 74 allowed for potential memory corruption and privilege escalation, which could be exploited to execute arbitrary code. The vulnerability was classified as a critical flaw in Firefox's security model.
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
< 74.0CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 checksWork through these to decide whether this CVE applies to you.
-
Check Firefox version in-browserOpen Firefox and navigate to about:support or go to Help > About Firefox to view the version numberAffected if Version shown is below 74.0 (for example, 73.0.1, 72.0.x, etc.)
-
Check Firefox version from command lineRun 'firefox --version' in terminal/command prompt, or on Linux check dpkg -l | grep -i firefox or rpm -qa | grep -i firefoxAffected if Version output is less than 74.0
-
Check Firefox via system package managerOn Windows: Open Settings > Apps > Apps & features and search for Firefox, or check Add/Remove Programs. On macOS: Right-click Firefox in Applications and select Get Info. On Linux: Query package databaseAffected if Installed Firefox package version is listed as below 74.0
-
Check registry for Firefox version on WindowsOpen Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox\CurrentVersion (or HKLM\SOFTWARE\WOW6432Node\Mozilla\Mozilla Firefox)Affected if The CurrentVersion value is less than 74.0
User is affected if any installed Firefox version is below 74.0
Generated from the published advisory. Verify against your own configuration.
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 · scoped74.0
Upgrade Mozilla Firefox to version 74 or later to remediate this vulnerability. In enterprise environments, deploy the updated browser version through standard software distribution mechanisms.
Firefox 74.0 or later
- Open Firefox and navigate to Menu > Help > About Firefox to trigger a check for updates
- If an update is available, download and install Firefox 74.0 or later
- Alternatively, download the latest Firefox version from the official Mozilla website (www.mozilla.org)
- After installation, verify the version by navigating to Menu > Help > About Firefox to confirm version 74.0 or newer is installed
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
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 locallyCheck whether your project pulls in CVE-2020-6815 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-6815 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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