GnuPG: ElGamal signing keys compromised [LWN.net]

Package(s):

gnupg

CVE #(s):

CAN-2003-0971

Created:

November 28, 2003

Updated:

March 3, 2004

Description:

A severe vulnerability was discovered in GnuPG by Phong Nguyen relating to ElGamal sign+encrypt keys. This email message from Werner Koch contains more information. "Phong Nguyen identified a severe bug in the way GnuPG creates and uses ElGamal keys for signing. 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."

Alerts:

SCO Group	CSSA-2004-009.0	2004-03-02
Debian	DSA-429-2	2004-02-13
Debian	DSA-429-1	2004-01-26
Gentoo	200312-05	2003-12-12
Fedora	FEDORA-2003-025	2003-12-10
Red Hat	RHSA-2003:395-01	2003-12-10
Red Hat	RHSA-2003:390-01	2003-12-10
Conectiva	CLA-2003:798	2003-12-09
SuSE	SuSE-SA:2003:048	2003-12-03
Mandrake	MDKSA-2003:109	2003-11-28

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GnuPG: ElGamal signing keys compromised

Posted Dec 4, 2003 3:31 UTC (Thu) by freethinker (guest, #4397) [Link]

Keysigning party, anyone? ;)

ElGamal signing keys are rare!

Posted Dec 8, 2003 11:53 UTC (Mon) by ber (subscriber, #2142) [Link]

It is important to note that creating those kind of keys was discouraged and only possible by deliberately disabling the safety meatures.

See those quotes from Werner's email (my emphasis):

Note that the standard keys as generated by GnuPG (DSA and ElGamal encryption) as well as RSA keys are NOT vulnerable. Note also that ElGamal signing keys cannot be generated without the use of a special flag to enable hidden options and even then overriding a warning message about this key type.

According to the keyserver statistics, there are 848 primary ElGamal signing keys which are affected. These are a mere 0.04 percent of all primary keys on the keyservers. There are 324 vulnerable subkeys on the keyservers, too.

Red Hat RHSA-2003:390 is out for this

Posted Dec 11, 2003 12:56 UTC (Thu) by bjn (guest, #2179) [Link]

Link: RHSA-2003:390