CVE Database›Document archive›CVE-2006-4339

CVE-2006-4339

OpenSSL: OpenSSL: Signature forgery via improper PKCS-1 padding removal leading to certificate validation bypass

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Severity

Critical

Red Hat Product Security

9.1

CVSS 3.1

Review impact separately from score.

Published · September 6, 2006

Updated · October 31, 2026

Description

A flaw was found in OpenSSL. When configured to use an RSA key with exponent 3, OpenSSL improperly removes PKCS-1 padding before generating a hash. This allows remote attackers to forge PKCS #1 v1.5 signatures. Consequently, OpenSSL may incorrectly verify X.509 and other certificates, leading to a bypass of trust and authentication mechanisms.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

CVSS / CWE

CVSS 3.1 · 9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CWE-347 · Improper Verification of Cryptographic Signature