GnuPG gpgv improper signature verification

gnupg-gpgv-improper-verification (24744)

Low Risk

Description:

GNU Privacy Guard (GnuPG or GPG) could allow certain detached signature files to bypass signature verification. If GnuPG is being used for unattended signature verification, the gpgv tool or gpg --verify command will show that signature verification for detached files has succeeded even if the detached file does not contain a valid signature. This would result in a loss of data integrity for digitally signed files.

*CVSS:

Base Score:	3.5
Access Vector:	Remote
Access Complexity:	Low
Authentication:	Not Required
Confidentiality Impact:	None
Integrity Impact:	Partial
Availability Impact:	None
Temporal Score:	2.6
Exploitability:	Unproven
Remediation Level:	Official-Fix
Report Confidence:	Confirmed

Consequences:

Other

Remedy:

Upgrade to the latest version of GnuPG (1.4.2.1 or later), available from GnuPG.org. See References.

For Debian Linux:
Refer to DSA-978-1 for upgrade information. See References.

For Ubuntu Linux:
Refer to USN-252-1 for upgrade information. See References.

For SUSE Linux:
Refer to SUSE Security Announcement: SUSE-SA:2006:009 for patch, upgrade, or suggested workaround information. See References.

For SUSE Linux:
Refer to SUSE Security Announcement SUSE-SA:2006:013 for patch, upgrade, or suggested workaround information. See References.

For Red Hat Linux:
Refer to RHSA-2006:0266-8 or RHSA-2006:0265-9 for patch, upgrade, or suggested workaround information. See References.

For Gentoo Linux:
Refer to Gentoo Linux Security Announcement GLSA 2006-02-10 for patch, upgrade, or suggested workaround information. See References.

For OpenPKG:
Refer to OpenPKG Security Advisory OpenPKG-SA-2006.001 for patch, upgrade, or suggested workaround information. See References.

For other distributions:
Contact your vendor for patch or upgrade information.

References:

• gnupg-announce Mailing List, Wed Feb 15 08:49:25 CET 2006: False positive signature verification in GnuPG.
• SGI Security Advisory 20060401-01-U: SGI Advanced Linux Environment 3 Security Update #56.
• ASA-2006-070: gnupg security update (RHSA-2006-0266)
• BID-16663: GnuPG Detached Signature Verification Bypass Vulnerability
• CVE-2006-0455: gpgv in GnuPG before 1.4.2.1, when using unattended signature verification, returns a 0 exit code in certain cases even when the detached signature file does not carry a signature, which could cause programs that use gpgv to assume that the signature verification has succeeded. Note: this also occurs when running the equivalent command gpg --verify.
• DSA-978: gnupg -- programming error
• GLSA-200602-08: libtasn1, GNU TLS: Security flaw in DER decoding
• GLSA-200602-10: GnuPG: Incorrect signature verification
• MDKSA-2006:043: Updated gnupg packages fix signature file verification vulnerability
• MDKSA-2006:055: Updated gnupg packages fix signature file verification vulnerability
• OpenPKG-SA-2006.001: GnuPG
• RHSA-2006-0266: gnupg security update
• SA18845: GnuPG "gpgv" Signature Verification Security Issue
• SUSE-SA:2006:009: gpg/liby2util incorrect gpg signature checking
• SUSE-SA:2006:013: gpg / liby2util signature checking problems
• SUSE-SA:2006:014: gpg signature checking problems
• SUSE-SR:2006:005: SUSE Security Summary Report
• USN-252-1: gnupg vulnerability
• VUPEN/ADV-2006-0610: GnuPG gpgv Signature Verification Security Bypass Vulnerability

Platforms Affected:

• Canonical Ubuntu 4.10
• Canonical Ubuntu 5.04
• Canonical Ubuntu 5.10
• Debian Debian Linux 3.0
• Debian Debian Linux 3.1
• Gentoo Linux
• GNU Privacy Guard 1.0
• GNU Privacy Guard 1.0.1
• GNU Privacy Guard 1.0.2
• GNU Privacy Guard 1.0.3
• GNU Privacy Guard 1.0.4
• GNU Privacy Guard 1.0.5
• GNU Privacy Guard 1.0.6
• GNU Privacy Guard 1.0.7
• GNU Privacy Guard 1.2
• GNU Privacy Guard 1.2.1
• GNU Privacy Guard 1.2.2
• GNU Privacy Guard 1.2.3
• GNU Privacy Guard 1.2.4
• GNU Privacy Guard 1.2.5
• GNU Privacy Guard 1.2.6
• GNU Privacy Guard 1.2.7
• GNU Privacy Guard 1.3.3
• GNU Privacy Guard 1.3.4
• GNU Privacy Guard 1.4
• GNU Privacy Guard 1.4.1
• GNU Privacy Guard 1.4.2
• MandrakeSoft Mandrake Linux 10.1 X86_64
• MandrakeSoft Mandrake Linux 10.1
• MandrakeSoft Mandrake Linux 2006 X86_64
• MandrakeSoft Mandrake Linux 2006
• MandrakeSoft Mandrake Linux LE2005 X86_64
• MandrakeSoft Mandrake Linux LE2005
• MandrakeSoft Mandrake Linux Corporate Server 2.1
• MandrakeSoft Mandrake Linux Corporate Server 2.1 X86_64
• MandrakeSoft Mandrake Linux Corporate Server 3.0 X86_64
• MandrakeSoft Mandrake Linux Corporate Server 3.0
• MandrakeSoft Mandrake Multi Network Firewall 2.0
• Novell Linux Desktop 9
• Novell Open Enterprise Server
• Novell Open Enterprise Server 1
• Novell Open Enterprise Server
• Novell UnitedLinux 1.0
• OpenPKG OpenPKG 2.3
• OpenPKG OpenPKG 2.4
• OpenPKG OpenPKG 2.5
• OpenPKG OpenPKG CURRENT
• RedHat Enterprise Linux 2.1 WS
• RedHat Enterprise Linux 2.1 AS
• RedHat Enterprise Linux 2.1 ES
• RedHat Enterprise Linux 3 WS
• RedHat Enterprise Linux 3 ES
• RedHat Enterprise Linux 3 Desktop
• RedHat Enterprise Linux 3 AS
• RedHat Enterprise Linux 4 WS
• RedHat Enterprise Linux 4 ES
• RedHat Enterprise Linux 4 AS
• RedHat Enterprise Linux 4 Desktop
• RedHat Linux Advanced Workstation 2.1 Itanium
• SGI Advanced Linux Environment 3
• SuSE Linux Enterprise Server 8
• SuSE Linux Enterprise Server 9
• SUSE SuSE Linux 10.0
• SUSE SuSE Linux 9.1
• SUSE SuSE Linux 9.2
• SUSE SuSE Linux 9.3
• SuSE SuSE Linux Desktop 1.0
• SuSE SuSE SLES 9

Reported:

Feb 15, 2006

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