CVE-2010-4180

Severity: medium (CVSS 4.3 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 9.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2010-12-06 · updated 2026-06-16

Description

OpenSSL before 0.9.8q, and 1.0.x before 1.0.0c, when SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG is enabled, does not properly prevent modification of the ciphersuite in the session cache, which allows remote attackers to force the downgrade to an unintended cipher via vectors involving sniffing network traffic to discover a session identifier.

Affected products

Canonical Ubuntu Linux: 6.06, 8.04, 9.04, 10.04, 10.10
Debian Linux: 5.0
nginx: before 0.9.2 — fixed in 0.9.2
Fedoraproject Fedora: 13, 14
OpenSSL: before 0.9.8q; from 1.0.0 before 1.0.0c — fixed in 0.9.8q, 1.0.0c
Opensuse: 11.1, 11.2, 11.3, 11.4
SUSE Linux Enterprise: 11.0-sp1
SUSE Linux Enterprise Server 15 SP1: 10-sp3, 10-sp4, 11-sp1
SUSE Linux Enterprise Server: 9, 10-sp3, 10-sp4

How to fix

Upgrade to a fixed version: nginx 0.9.2; OpenSSL 0.9.8q, 1.0.0c. Check the vendor advisory for mitigations.

References

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