FirefoxWeb browser · Mozilla
CVE-2016-5260
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 Firefox before 48.0 mishandles changes from 'INPUT type="password"' to 'INPUT type="text"' within a single Session Manager session, which might allow attackers to discover cleartext passwords by reading a session restoration file.
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 confidenceIn Firefox before 48.0, the Session Manager feature incorrectly handles form field type changes from 'password' to 'text' within a saved session. When a user modifies a password input field to a text field during a session, the session restoration file stores the actual password value in cleartext rather than masking it, allowing attackers with file access to read stored credentials.
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
<= 47.0.1CVSS 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:3.0/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 checksWork through these to decide whether this CVE applies to you.
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Check Firefox versionGo to Help > About Firefox or visit about:support to see the installed version numberAffected if Version is 47.0.1 or earlier (any version <= 47.0.1)
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Verify Session Manager extension is installedIn Firefox, go to Add-ons > Extensions and look for 'Session Manager' or check the extensions.ini file in the profile directory for session manager entriesAffected if Session Manager extension is present and enabled
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Locate session restoration filesIn the Firefox profile directory, look for session files in the sessionmanager-backups folder or similar session storage locations (sessionstore.jsonlz4, sessionstore.bak, etc.)Affected if Session restoration files exist in the profile directory
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Inspect session files for cleartext passwordsOpen session restoration files with a text editor or parse the JSON structure and search for input type='text' fields containing what appears to be password data (look for form fields where type changed from password to text)Affected if Session files contain unmasked password values in form field data
You are affected if you run Firefox version 47.0.1 or earlier, have the Session Manager extension installed, and have saved sessions that were modified to change password fields to text fields, resulting in stored cleartext passwords in session files.
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 Firefox to version 48.0 or later. Alternatively, avoid using Session Manager to save sessions that contain password fields, or ensure session restoration files are protected with appropriate file system permissions.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 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 $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-5260 — 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-2016-5260 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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