Messagepack RsApplication · Messagepack Rs Project
CVE-2021-45691
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_string 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 · high confidenceThe messagepack-rs crate through early 2021 has a memory safety vulnerability in the deserialize_string function, which may read from uninitialized memory locations. This could lead to information disclosure or undefined behavior during MessagePack deserialization.
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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Locate the messagepack-rs dependencySearch your project files (Cargo.toml and Cargo.lock) for 'messagepack-rs', 'msgpack', or 'rmp' as a dependency. Also check any lockfiles or dependency manifests that may reference this crate.Affected if The crate appears as a direct or transitive dependency in your project
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Identify the installed versionOpen Cargo.lock and find the version number listed next to the messagepack-rs crate entry. Alternatively, run 'cargo tree -p messagepack-rs' if the crate is named messagepack-rs in your project.Affected if The version is lower than 0.8.1 (for example: 0.8.0, 0.7.0, etc.)
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Confirm deserialization usageSearch your codebase for calls to deserialize, unpack, or read functions that process MessagePack data, particularly those handling string types. Look for usage of Deserializer::deserialize_string() or equivalent APIs.Affected if Your code deserializes MessagePack string data, especially from network sources or files that may contain untrusted content
You are affected if messagepack-rs version 0.8.0 or lower is present in your dependency tree and your application deserializes MessagePack string data from external or untrusted sources.
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 the messagepack-rs crate; if unavailable, avoid deserializing string data from untrusted sources until a fix is released.
messagepack-rs version 0.8.1 or later
- Check your Cargo.toml file for the current messagepack-rs version dependency
- Update the messagepack-rs dependency version to 0.8.1 or later in Cargo.toml
- Run 'cargo update messagepack-rs' to fetch the fixed version
- Run 'cargo build' to compile with the updated dependency
- Run your application's test suite to verify the upgrade does not break existing functionality
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
- Implementation6.0 h
- Testing8.0 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 $5,152.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-45691 — 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-2021-45691 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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