CVE-2021-45691 — Messagepack-Rs
CRITICALCVE-2021-45691 is a critical-severity (CVSS 9.8) CWE-908 vulnerability in messagepack-rs_project messagepack-rs. A fix is available — see the affected versions and patch details below.
An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_string may read from uninitialized memory locations.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-45691 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_string may read from uninitialized memory locations.
Affected Products
messagepack-rsmessagepack-rs_projectDetection & mitigation playbook
Vendor / applianceDetect
Inventory every messagepack-rs_project messagepack-rs deployment and check each version against the affected-products list above.
Fix
Apply the messagepack-rs_project messagepack-rs security patch or hotfix for CVE-2021-45691 on the affected version, following the vendor advisory for your exact build.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2021-45691 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.