BeefApplication · Beef Project
CVE-2020-36442
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 beef crate before 0.5.0 for Rust. beef::Cow has no Sync bound on its Send trait.
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 confidenceIn the beef crate before version 0.5.0, the beef::Cow type incorrectly implements Send without implementing Sync. This violates Rust's memory safety guarantees, as a type that is Send but not Sync should not be shareable across thread boundaries. The missing Sync bound can lead to data races and undefined behavior when the type is used in multi-threaded contexts.
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
BeefApplication
< 0.5.0CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/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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Check if beef crate is a dependencyExamine your project's Cargo.toml file and look for 'beef' in the [dependencies] section, or search Cargo.lock for 'name = "beef"' to confirm the crate is included.Affected if The beef crate appears as a dependency in your project.
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Determine the installed beef versionFind the version number next to the beef entry in Cargo.lock, or run 'cargo tree -p beef' to see the exact version being used.Affected if The installed version is less than 0.5.0.
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Search for beef::Cow usage in source codeSearch your Rust source files for 'beef::Cow' or 'use beef::Cow' to determine if the vulnerable type is being used.Affected if Your code explicitly uses the beef::Cow type.
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Check for multi-threaded usage of beef::CowInspect any code paths where beef::Cow is passed between threads, shared across thread boundaries, or used in concurrent data structures. Look for .move() calls involving Cow, threading primitives, or Send/Sync trait bounds.Affected if The beef::Cow type is used in multi-threaded contexts such as passing to other threads, spawning tasks, or storing in shared concurrent structures.
You are affected if the beef crate version is below 0.5.0 AND your code uses beef::Cow in multi-threaded contexts, since only then can the Send-without-Sync violation lead to actual data races.
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 · scoped0.5.0
Upgrade the beef crate to version 0.5.0 or later. Review any code using beef::Cow to ensure no data races were introduced prior to the update.
beef 0.5.0
- Update the beef crate dependency in your Cargo.toml file to version 0.5.0 or later
- Run `cargo update` to fetch the updated dependency
- Run `cargo build` or `cargo test` to verify the fix compiles correctly
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Beef
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 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 $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-36442 — 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-2020-36442 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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