OpenSSL, AMD64 x86 emulation base libraries: RSA signature forgery

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200609-05 / openssl
Release Date	September 07, 2006
Latest Revision	September 08, 2006: 02
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
dev-libs/openssl	< 0.9.7k	>= 0.9.7k	All supported architectures
app-emulation/emul-linux-x86-baselibs	< 2.5.2	>= 2.5.2	AMD64

Related bugreports: #146375, #146438

Synopsis

OpenSSL fails to properly validate PKCS #1 v1.5 signatures.

2. Impact Information

Background

OpenSSL is a toolkit implementing the Secure Sockets Layer, Transport Layer Security protocols and a general-purpose cryptography library. The x86 emulation base libraries for AMD64 contain a vulnerable version of OpenSSL.

Description

Daniel Bleichenbacher discovered that it might be possible to forge signatures signed by RSA keys with the exponent of 3.

Impact

Since several CAs are using an exponent of 3 it might be possible for an attacker to create a key with a false CA signature.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All OpenSSL users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/openssl-0.9.7k"

All AMD64 x86 emulation base libraries users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=app-emulation/emul-linux-x86-baselibs-2.5.2"

4. References

CVE-2006-4339

Page updated September 07, 2006

Summary: This is a Gentoo Linux Security Advisory

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