RHEL 2.1 / 3 : gnupg (RHSA-2003:395)

medium Nessus Plugin ID 12439

Synopsis

The remote Red Hat host is missing a security update.

Description

Updated gnupg packages are now available for Red Hat Enterprise Linux.
These updates disable the ability to generate ElGamal keys (used for both signing and encrypting) and disable the ability to use ElGamal public keys for encrypting data.

GnuPG is a utility for encrypting data and creating digital signatures.

Phong Nguyen identified a severe bug in the way GnuPG creates and uses ElGamal keys, when those keys are used both to sign and encrypt data.
This vulnerability can be used to trivially recover the private key.
While the default behavior of GnuPG when generating keys does not lead to the creation of unsafe keys, by overriding the default settings an unsafe key could have been created.

If you are using ElGamal keys, you should revoke those keys immediately.

The packages included in this update do not make ElGamal keys safe to use; they merely include a patch by David Shaw that disables functions that would generate or use ElGamal keys.

To determine if your key is affected, run the following command to obtain a list of secret keys that you have on your secret keyring :

gpg --list-secret-keys

The output of this command includes both the size and type of the keys found, and will look similar to this example :

/home/example/.gnupg/secring.gpg
---------------------------------------------------- sec 1024D/01234567 2000-10-17 Example User <[email protected]> uid Example User <[email protected]>

The key length, type, and ID are listed together, separated by a forward slash. In the example output above, the key's type is 'D' (DSA, sign and encrypt). Your key is unsafe if and only if the key type is 'G' (ElGamal, sign and encrypt). In the above example, the secret key is safe to use, while the secret key in the following example is not :

/home/example/.gnupg/secring.gpg
---------------------------------------------------- sec 1024G/01234567 2000-10-17 Example User <[email protected]> uid Example User <[email protected]>

For more details regarding this issue, as well as instructions on how to revoke any keys that are unsafe, refer to the advisory available from the GnuPG website :

http://www.gnupg.org/

Solution

Update the affected gnupg package.

Plugin Details

Severity: Medium

ID: 12439

File Name: redhat-RHSA-2003-395.nasl

Version: 1.28

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 7/6/2004

Updated: 1/14/2021

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v2

Risk Factor: Medium

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:2.1, cpe:/o:redhat:enterprise_linux:3, p-cpe:/a:redhat:enterprise_linux:gnupg

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Patch Publication Date: 12/10/2003

Vulnerability Publication Date: 12/15/2003

Reference Information

CVE: CVE-2003-0971

RHSA: 2003:395

Detections

Analytics