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Debian dla-4195 : krb5-admin-server - security update

medium Nessus Plugin ID 237586

Synopsis

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

Description

The remote Debian 11 host has packages installed that are affected by a vulnerability as referenced in the dla-4195 advisory.

 - ------------------------------------------------------------------------- Debian LTS Advisory DLA-4195-1 [email protected] https://www.debian.org/lts/security/ Bastien Roucaris May 30, 2025 https://wiki.debian.org/LTS
 - -------------------------------------------------------------------------

 Package : krb5 Version : 1.18.3-6+deb11u7 CVE ID : CVE-2025-3576 Debian Bug : 1103525

 A Vulnerability in the MIT Kerberos implementation allows GSSAPI-protected messages using RC4-HMAC-MD5 to be spoofed due to weaknesses in the MD5 checksum design.
 If RC4 is preferred over stronger encryption types, an attacker could exploit MD5 collisions to forge message integrity codes. This may lead to unauthorized message tampering.

 In order to fix CVE-2025-3576, vulnerable cryptographic algorithms for tickets need to be disabled explicitly with the new allow_rc4 or allow_des3 variables.

 According to the vulnerability report Kerberos?? RC4-HMAC broken in practice: spoofing PACs with MD5 collisions, disabling this cryptographic algorithm may break some older authentication systems, and administrators should test carefully.

 Because of the risk of breaking certain configurations, the new allow_rc4 or allow_des3 are being treated as having a default value of 'true' for updates to older Debian releases.
 This leaves the 3DES and RC4 algorithms enabled, but administrators are strongly encouraged to disable them after verifying compatibility in their environments.

 For Debian 11 bullseye, this problem has been fixed in version 1.18.3-6+deb11u7.

 We recommend that you upgrade your krb5 packages.

 For the detailed security status of krb5 please refer to its security tracker page at:
 https://security-tracker.debian.org/tracker/krb5

 Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade the krb5-admin-server packages.

See Also

https://security-tracker.debian.org/tracker/source-package/krb5

https://security-tracker.debian.org/tracker/CVE-2025-3576

https://packages.debian.org/source/bullseye/krb5

Plugin Details

Severity: Medium

ID: 237586

File Name: debian_DLA-4195.nasl

Version: 1.1

Type: local

Agent: unix

Published: 5/30/2025

Updated: 5/30/2025

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

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4

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

CVSS Score Source: CVE-2025-3576

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, p-cpe:/a:debian:debian_linux:krb5-pkinit, p-cpe:/a:debian:debian_linux:libkrb5support0, p-cpe:/a:debian:debian_linux:krb5-gss-samples, p-cpe:/a:debian:debian_linux:libkrad0, p-cpe:/a:debian:debian_linux:libkadm5clnt-mit12, p-cpe:/a:debian:debian_linux:libkrad-dev, p-cpe:/a:debian:debian_linux:krb5-kdc, p-cpe:/a:debian:debian_linux:krb5-otp, p-cpe:/a:debian:debian_linux:krb5-admin-server, p-cpe:/a:debian:debian_linux:libgssapi-krb5-2, p-cpe:/a:debian:debian_linux:libkrb5-dev, p-cpe:/a:debian:debian_linux:libkdb5-10, p-cpe:/a:debian:debian_linux:krb5-multidev, p-cpe:/a:debian:debian_linux:libgssrpc4, p-cpe:/a:debian:debian_linux:libk5crypto3, p-cpe:/a:debian:debian_linux:libkrb5-dbg, p-cpe:/a:debian:debian_linux:krb5-locales, p-cpe:/a:debian:debian_linux:krb5-user, p-cpe:/a:debian:debian_linux:libkadm5srv-mit12, p-cpe:/a:debian:debian_linux:libkrb5-3, p-cpe:/a:debian:debian_linux:krb5-kpropd, p-cpe:/a:debian:debian_linux:krb5-doc, p-cpe:/a:debian:debian_linux:krb5-k5tls, p-cpe:/a:debian:debian_linux:krb5-kdc-ldap

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

Exploit Ease: No known exploits are available

Patch Publication Date: 5/30/2025

Vulnerability Publication Date: 4/15/2025

Reference Information

CVE: CVE-2025-3576