Firefox OsOperating system · Mozilla
CVE-2015-8511
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 · uneditedRace condition in the lockscreen feature in Mozilla Firefox OS before 2.5 allows physically proximate attackers to bypass an intended passcode requirement via unspecified vectors.
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 confidenceA race condition in the lockscreen authentication mechanism of Mozilla Firefox OS versions prior to 2.5 allows a physically proximate attacker to bypass the passcode requirement. The vulnerability exploits timing or sequencing issues in the lockscreen unlock flow.
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
Firefox OsOperating system
<= 2.2CVSS 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
- Physical
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:P/AC:H/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.
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Identify if the device runs Firefox OSCheck the device OS information in system settings or boot sequence. Firefox OS was used on certain smartphones (e.g., ZTE Open, Flame, Peak). Look for 'Firefox OS' in the About/Device Info screen.Affected if The device is not running Firefox OS - this CVE does not apply to other operating systems.
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Determine the Firefox OS versionNavigate to Settings > About Phone > Software Information on the Firefox OS device. Locate the 'Software version' or 'Build number' entry.Affected if The installed version is 2.2 or lower (any version prior to 2.5). Versions 2.5 and later are not affected.
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Verify if lockscreen passcode protection is enabledGo to Settings > Screen Lock on the Firefox OS device. Check whether a passcode, PIN, or password is set for the lockscreen.Affected if A passcode/PIN/password is configured on the lockscreen. The vulnerability only affects devices that have passcode protection enabled.
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Confirm physical access scenario appliesConsider whether the device could be accessed by physically proximate (untrusted) individuals in your threat model.Affected if The device is used in contexts where untrusted parties could gain brief physical access (e.g., shared devices, public kiosks, unattended devices in public spaces).
The device is affected if it runs Firefox OS version 2.2 or lower AND has a lockscreen passcode enabled AND is at risk of physical access by untrusted individuals.
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.
From vendor dataUpgrade to Firefox OS 2.5 or later; for legacy systems, consider disabling lockscreen passcode features or implementing additional authentication layers until patching is possible.
Fix this in Firefox Os
Scoped from the published advisory
- Consultation2.0 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 $1,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-8511 — 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-2015-8511 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
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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
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