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Debian DSA-269-1 : heimdal - Cryptographic weakness

high Nessus Plugin ID 15106

Synopsis

The remote Debian host is missing a security-related update.

Description

A cryptographic weakness in version 4 of the Kerberos protocol allows an attacker to use a chosen-plaintext attack to impersonate any principal in a realm. Additional cryptographic weaknesses in the krb4 implementation permit the use of cut-and-paste attacks to fabricate krb4 tickets for unauthorized client principals if triple-DES keys are used to key krb4 services. These attacks can subvert a site's entire Kerberos authentication infrastructure.

This version of the heimdal package changes the default behavior and disallows cross-realm authentication for Kerberos version 4. Because of the fundamental nature of the problem, cross-realm authentication in Kerberos version 4 cannot be made secure and sites should avoid its use. A new option (--kerberos4-cross-realm) is provided to the kdc command to re-enable version 4 cross-realm authentication for those sites that must use this functionality but desire the other security fixes.

Solution

Upgrade the heimdal packages immediately.

For the stable distribution (woody) this problem has been fixed in version 0.4e-7.woody.8.

The old stable distribution (potato) is not affected by this problem, since it isn't compiled against kerberos 4.

See Also

http://www.debian.org/security/2003/dsa-269

Plugin Details

Severity: High

ID: 15106

File Name: debian_DSA-269.nasl

Version: 1.21

Type: local

Agent: unix

Published: 9/29/2004

Updated: 1/4/2021

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.7

CVSS v2

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:3.0, p-cpe:/a:debian:debian_linux:heimdal

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Patch Publication Date: 3/26/2003

Reference Information

CVE: CVE-2003-0138

CERT: 623217

DSA: 269