CVE-2011-0910
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 · uneditedThe cookie implementation in Vanilla Forums before 2.0.17.6 makes it easier for remote attackers to spoof signed requests, and consequently obtain access to arbitrary user accounts, via HMAC timing attacks.
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 confidenceThe cookie implementation in Vanilla Forums before version 2.0.17.6 uses a vulnerable HMAC comparison susceptible to timing attacks. Attackers can measure response times from crafted cookie values to incrementally guess valid HMAC signatures, allowing them to forge authentication cookies and gain unauthorized access to arbitrary user accounts.
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<= 2.0.17.5= 2.0.9= 2.0.10= 2.0.11= 2.0.12= 2.0.13= 2.0.14= 2.0.15= 2.0.16= 2.0.17= 2.0.17.1= 2.0.17.2CVSS 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
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:P/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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Identify installed Vanilla Forums versionLocate the version file or changelog in the Vanilla Forums installation directory. Common locations include a version.php file, a changelog file, or the admin dashboard version display.Affected if The installed version is 2.0.17.5 or lower, or exactly matches any of these versions: 2.0.9, 2.0.10, 2.0.11, 2.0.12, 2.0.13, 2.0.14, 2.0.15, 2.0.16, 2.0.17, 2.0.17.1, or 2.0.17.2
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Locate the cookie authentication codeSearch the Vanilla Forums source code for the HMAC comparison function used during cookie validation. Look for functions that verify the cookie signature or HMAC hash.Affected if The code uses a standard string comparison operator (like == or !==) rather than a constant-time comparison function to validate the HMAC signature.
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Verify timing-safe comparison is absentExamine the authentication library or security functions for the presence of a constant-time comparison method such as hash_equals() or a timing-safe comparison routine.Affected if No constant-time comparison function is found in the cookie validation logic, meaning the HMAC comparison is vulnerable to timing attacks.
A user is affected if their Vanilla Forums installation is version 2.0.17.5 or lower, or matches any of the specific affected versions 2.0.9 through 2.0.17.2, and the cookie HMAC validation uses a timing-vulnerable string comparison rather than a constant-time comparison method.
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 Vanilla Forums 2.0.17.6 or later, which implements constant-time HMAC comparison to defeat timing attacks.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-0910 — 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-2011-0910 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
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data