CVE-2011-4354

Severity: medium (CVSS 5.8 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2012-01-27 · updated 2026-06-16
Weakness: CWE-310

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.

Affected products

OpenSSL: through 0.9.8g; 0.9.1c, 0.9.2b, 0.9.3, 0.9.3a, 0.9.4, 0.9.5 (+52)

References

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

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