GoApplication · Golang
CVE-2020-29509
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 encoding/xml package in Go (all versions) does not correctly preserve the semantics of attribute namespace prefixes during tokenization round-trips, which allows an attacker to craft inputs that behave in conflicting ways during different stages of processing in affected downstream applications.
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 confidenceThe encoding/xml package in Go fails to preserve attribute namespace prefix semantics during XML tokenization round-trips. An attacker can craft malicious XML inputs with conflicting namespace prefix behaviors that differ between parsing and re-serialization stages, potentially bypassing security checks in downstream applications that rely on consistent namespace handling.
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
GoApplication
< 1.17all versionsCVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
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 the installed Go versionRun 'go version' in the environment or check the Go binary path used by the applicationAffected if The Go version is 1.16.x or earlier (prior to 1.17)
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Identify applications using encoding/xml for XML processingSearch codebase for 'import "encoding/xml"' statements or review application dependencies for the encoding/xml packageAffected if The application imports and uses the encoding/xml package
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Determine if XML round-trip operations are performedSearch for code patterns that parse XML then re-serialize it (e.g., calls to xml.Unmarshal followed by xml.Marshal, or xml.Decoder token operations that output the result)Affected if The application performs both XML parsing (unmarshal/decoding) and re-serialization (marshal/encoding) on the same data
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For Netapp Trident: identify the Trident installationCheck for Trident deployment using 'tridentctl version' or review container/orchestrator manifests for Trident componentsAffected if Netapp Trident is deployed in the environment (all versions are affected)
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For Netapp Trident: determine the Go version used to build TridentReview Trident release notes or build documentation to identify the Go version Trident was compiled with, or inspect Trident container images for the embedded Go versionAffected if Trident was built with Go version < 1.17
A user is affected if their environment uses Go versions prior to 1.17 (or any Netapp Trident version) AND their application performs XML parsing followed by re-serialization using the encoding/xml package, where namespace prefix handling could differ between stages.
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 data1.17
Update Go to a patched version when available. In the interim, implement explicit namespace validation and normalization on XML inputs before processing, and verify that security-critical XML operations check namespace consistency rather than relying solely on prefix matching.
Fix this in Go
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-29509 — 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-2020-29509 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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- Version or environment caveats, and links to real fixes
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