Crypto2Application · Crypto2 Project
CVE-2021-45709
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 crypto2 crate through 2021-10-08 for Rust. During Chacha20 encryption and decryption, an unaligned read of a u32 may occur.
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 crypto2 Rust crate has a memory alignment bug in its ChaCha20 implementation where unaligned 32-bit reads occur during both encryption and decryption operations. This can cause undefined behavior including potential crashes on architectures with strict alignment requirements, performance degradation, or memory corruption issues.
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
Crypto2Application
all 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
- 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.
-
Identify crypto2 crate usageSearch your project dependencies (Cargo.toml, Cargo.lock) for the crypto2 crate entryAffected if The crypto2 crate is listed as a dependency
-
Determine crypto2 versionInspect the Cargo.lock file or run 'cargo tree -p crypto2' to see the exact version number of the crypto2 crate installedAffected if Any version of crypto2 is present (the vulnerability affects all versions)
-
Verify ChaCha20 usageSearch source code for ChaCha20 usage patterns: direct imports (use crypto2::cipher::stream::{StreamCipher, ChaCha20}), cipher instantiation, or crypto2::chacha20 module referencesAffected if ChaCha20 from crypto2 is being instantiated or used in encryption/decryption operations
-
Check target architecture alignment sensitivityReview your build target (cargo build --target) - architectures with strict alignment requirements (some ARM variants, SPARC, etc.) are more susceptible to undefined behavior from unaligned readsAffected if Building for architectures with strict alignment requirements while using ChaCha20 from crypto2
Your environment is affected if the crypto2 crate is in your dependency tree and ChaCha20 operations from that crate are being performed, regardless of version since all versions contain the alignment flaw.
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 dataUpdate the crypto2 crate to a version beyond 2021-10-08 that contains the proper memory alignment fix for ChaCha20 operations. Verify all cryptographic operations function correctly after the update.
Fix this in Crypto2
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-2021-45709 — 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-2021-45709 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data