CVE-2012-2921
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 · uneditedUniversal Feed Parser (aka feedparser or python-feedparser) before 5.1.2 allows remote attackers to cause a denial of service (memory consumption) via a crafted XML ENTITY declaration in a non-ASCII encoded document.
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 confidenceUniversal Feed Parser (python-feedparser) before version 5.1.2 is vulnerable to a denial-of-service attack via crafted XML ENTITY declarations in non-ASCII encoded documents. The vulnerability allows remote attackers to cause excessive memory consumption by triggering recursive or exponential entity expansion during XML parsing.
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<= 5.1.1= 3.0= 3.0.1= 3.1= 3.2= 3.3= 4.0= 4.0.1= 4.0.2= 4.1= 5.0= 5.0.1CVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 feedparser versionRun 'pip show feedparser' or 'python -c "import feedparser; print(feedparser.__version__)"' to get the installed version numberAffected if The version is 5.1.1 or earlier, or matches any of these: 3.0, 3.0.1, 3.1, 3.2, 3.3, 4.0, 4.0.1, 4.0.2, 4.1, 5.0, 5.0.1
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Check for feeds with non-ASCII encodingInspect your feed sources or logs for feeds that use non-ASCII character encodings (such as UTF-16, UTF-32, or regional encodings)Affected if Your application processes XML feeds with non-ASCII encodings from untrusted sources
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Confirm XML parsing is enabledReview your application code to verify that feedparser is used to parse XML-based feeds (RSS, Atom)Affected if Your application uses feedparser to parse XML feeds from external sources
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Verify external feed input handlingCheck if your application accepts and parses feeds from external/untrusted sources without prior sanitizationAffected if Your application parses feeds from untrusted or remote sources directly through feedparser
You are affected if your installed feedparser version is 5.1.1 or earlier (or specifically matches versions 3.0 through 5.0.1) AND your application parses XML feeds from external sources, especially those with non-ASCII encodings.
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 feedparser to version 5.1.2 or later to patch the XML entity expansion vulnerability. If upgrade is not immediately possible, consider sanitizing or validating feed input before parsing, or implementing resource limits on XML parsing operations.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-2921 — 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-2012-2921 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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