CVE-2011-4354

MEDIUM

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.

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

Details

Source: MITRE

Published: 2012-01-27

Updated: 2012-11-06

Type: CWE-310

Risk Information

CVSS v2.0

Base Score: 5.8

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N

Impact Score: 4.9

Exploitability Score: 8.6

Severity: MEDIUM