Messagepack RsApplication · Messagepack Rs Project
CVE-2021-45692
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 · uneditedAn issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_extension_others may read from uninitialized memory locations.
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 messagepack-rs crate for Rust contains a memory safety vulnerability where the deserialize_extension_others function may read from uninitialized memory locations. This is undefined behavior that could potentially lead to information disclosure or unpredictable application behavior when deserializing MessagePack data containing extension types.
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
Messagepack RsApplication
< 0.8.1CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/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 messagepack-rs in dependenciesSearch your project's Cargo.toml file for 'messagepack-rs' or 'msgpack' in the [dependencies] sectionAffected if The crate is listed as a dependency with a version lower than 0.8.1
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Check the exact installed versionInspect your Cargo.lock file and search for the messagepack-rs crate entry to find the resolved version numberAffected if The version field shows a number less than 0.8.1 (e.g., 0.8.0, 0.7.0, etc.)
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Identify deserialization of extension typesSearch your codebase for calls to deserialize methods (deserialize, deserialize_from, or unpack) that process MessagePack data which may contain extension types (application-specific data with custom type IDs)Affected if Your application deserializes untrusted MessagePack data that includes extension types using the vulnerable function
Your environment is affected if messagepack-rs version 0.8.0 or lower is installed AND your application deserializes MessagePack data containing extension types.
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.
dbcve · scoped0.8.1
Update to a patched version of messagepack-rs that addresses this vulnerability. If no patched version is available, review all usage of the deserialization functions and consider adding input validation or switching to an alternative serialization library.
msgpack crate version 0.8.1 or later
- Update the Cargo.toml file to specify version 0.8.1 or later of the msgpack crate: Change 'msgpack = "<0.8.1"' to 'msgpack = "0.8.1"' or use a semver compatible version like 'msgpack = ">=0.8.1"'
- Run 'cargo update msgpack' to fetch the updated version
- Run 'cargo build' or 'cargo test' to verify the update works correctly with your project
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Messagepack Rs
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-45692 — 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-2021-45692 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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