GLSA 200312-05: GnuPG: ElGamal signing keys compromised and format string vulnerability

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Severity:	translation missing: en, label_glsa_minimal
Title:	GnuPG: ElGamal signing keys compromised and format string vulnerability
Date:	12/12/2003
Bugs:	#34504
ID:	200312-05

Synopsis

A bug in GnuPG allows ElGamal signing keys to be compromised, and a format string bug in the gpgkeys_hkp utility may allow arbitrary code execution.

Background

GnuPG is a popular open source signing and encryption tool.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
app-crypt/gnupg	<= 1.2.3-r4	>= 1.2.3-r5	All supported architectures

Description

Two flaws have been found in GnuPG 1.2.3.

First, ElGamal signing keys can be compromised. These keys are not commonly used, but this is "a significant security failure which can lead to a compromise of almost all ElGamal keys used for signing. Note that this is a real world vulnerability which will reveal your private key within a few seconds".

Second, there is a format string flaw in the 'gpgkeys_hkp' utility which "would allow a malicious keyserver in the worst case to execute an arbitrary code on the user's machine."

Impact

If you have used ElGamal keys for signing your private key can be compromised, and a malicious keyserver could remotely execute arbitrary code with the permissions of the user running gpgkeys_hkp.

Workaround

There is no known workaround at this time.

Resolution

All users who have created ElGamal signing keys should immediately revoke them. In addition, all Gentoo Linux machines with gnupg installed should be updated to use gnupg-1.2.3-r5 or higher:

    # emerge sync
    # emerge -pv '>=app-crypt/gnupg-1.2.3-r5'
    # emerge '>=app-crypt/gnupg-1.2.3-r5'
    # emerge clean

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200312-05.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.