RHEL 2.1 : openssh (RHSA-2003:224)

High Nessus Plugin ID 12407


The remote Red Hat host is missing one or more security updates.


Updated OpenSSH packages are now available. These updates close an information leak caused by sshd's interaction with the PAM system.

OpenSSH is a suite of network connectivity tools that can be used to establish encrypted connections between systems on a network and can provide interactive login sessions and port forwarding, among other functions.

When configured to allow password-based or challenge-response authentication, sshd (the OpenSSH server) uses PAM (Pluggable Authentication Modules) to verify the user's password. Under certain conditions, OpenSSH versions prior to 3.6.1p1 reject an invalid authentication attempt without first attempting authentication using PAM.

If PAM is configured with its default failure delay, the amount of time sshd takes to reject an invalid authentication request varies widely enough that the timing variations could be used to deduce whether or not an account with a specified name existed on the server.
This information could then be used to narrow the focus of an attack against some other system component.

These updates contain backported fixes that cause sshd to always attempt PAM authentication when performing password and challenge-response authentication for clients.


Update the affected packages.

See Also



Plugin Details

Severity: High

ID: 12407

File Name: redhat-RHSA-2003-224.nasl

Version: $Revision: 1.23 $

Type: local

Agent: unix

Published: 2004/07/06

Modified: 2016/12/28

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.6

Temporal Score: 7.2

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

Temporal Vector: CVSS2#E:F/RL:ND/RC:ND

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:openssh, p-cpe:/a:redhat:enterprise_linux:openssh-askpass, p-cpe:/a:redhat:enterprise_linux:openssh-askpass-gnome, p-cpe:/a:redhat:enterprise_linux:openssh-clients, p-cpe:/a:redhat:enterprise_linux:openssh-server, cpe:/o:redhat:enterprise_linux:2.1

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2003/07/29

Vulnerability Publication Date: 2003/04/28

Reference Information

CVE: CVE-2003-0190, CVE-2003-1562

OSVDB: 2109, 2140

RHSA: 2003:224

CWE: 362