Synopsis
The remote Red Hat host is missing one or more security updates for krb5.
Description
The remote Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:567 advisory.
Kerberos is a networked authentication system that uses a trusted third party (a KDC) to authenticate clients and servers to each other.
A double-free flaw was found in the krb5_recvauth() routine which may be triggered by a remote unauthenticated attacker. Red Hat Enterprise Linux 4 contains checks within glibc that detect double-free flaws. Therefore, on Red Hat Enterprise Linux 4 successful exploitation of this issue can only lead to a denial of service (KDC crash). The Common Vulnerabilities and Exposures project assigned the name CAN-2005-1689 to this issue.
Daniel Wachdorf discovered a single byte heap overflow in the krb5_unparse_name() function, part of krb5-libs. Sucessful exploitation of this flaw would lead to a denial of service (crash). To trigger this flaw an attacker would need to have control of a kerberos realm that shares a cross-realm key with the target, making exploitation of this flaw unlikely.
(CAN-2005-1175).
Daniel Wachdorf also discovered that in error conditions that may occur in response to correctly-formatted client requests, the Kerberos 5 KDC may attempt to free uninitialized memory. This could allow a remote attacker to cause a denial of service (KDC crash) (CAN-2005-1174).
Gal Delalleau discovered an information disclosure issue in the way some telnet clients handle messages from a server. An attacker could construct a malicious telnet server that collects information from the environment of any victim who connects to it using the Kerberos-aware telnet client (CAN-2005-0488).
The rcp protocol allows a server to instruct a client to write to arbitrary files outside of the current directory. This could potentially cause a security issue if a user uses the Kerberos-aware rcp to copy files from a malicious server (CAN-2004-0175).
All users of krb5 should update to these erratum packages, which contain backported patches to correct these issues. Red Hat would like to thank the MIT Kerberos Development Team for their responsible disclosure of these issues.
Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the RHEL krb5 package based on the guidance in RHSA-2005:567.
Plugin Details
File Name: redhat-RHSA-2005-567.nasl
Agent: unix
Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus
Risk Information
Vendor
Vendor Severity: Important
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
CPE: cpe:/o:redhat:enterprise_linux:4, p-cpe:/a:redhat:enterprise_linux:krb5-workstation, p-cpe:/a:redhat:enterprise_linux:krb5-server, p-cpe:/a:redhat:enterprise_linux:krb5, p-cpe:/a:redhat:enterprise_linux:krb5-libs, p-cpe:/a:redhat:enterprise_linux:krb5-devel
Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu
Patch Publication Date: 7/12/2005
Vulnerability Publication Date: 8/18/2004