Security update for krb5

Announcement ID: SUSE-SU-2025:3698-1
Release Date: 2025-10-21T10:07:22Z
Rating: moderate
References:
Cross-References:
CVSS scores:
  • CVE-2025-3576 ( SUSE ): 8.2 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
  • CVE-2025-3576 ( SUSE ): 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
  • CVE-2025-3576 ( NVD ): 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Affected Products:
  • SUSE Linux Enterprise Server 12 SP5
  • SUSE Linux Enterprise Server 12 SP5 LTSS Extended Security
  • SUSE Linux Enterprise Server for SAP Applications 12 SP5

An update that solves one vulnerability can now be installed.

Description:

This update for krb5 fixes the following issues:

  • CVE-2025-3576: weakness in the MD5 checksum design allows for spoofing of GSSAPI-protected messages that are using RC4-HMAC-MD5 (bsc#1241219).

Krb5 as very old protocol supported quite a number of ciphers that are not longer up to current cryptographic standards.

To avoid problems with those, SUSE has by default now disabled those alorithms.

The following algorithms have been removed from valid krb5 enctypes:

  • des3-cbc-sha1
  • arcfour-hmac-md5

To reenable those algorithms, you can use allow options in krb5.conf:

[libdefaults] allow_des3 = true allow_rc4 = true

to reenable them.

Patch Instructions:

To install this SUSE update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Alternatively you can run the command listed for your product:

  • SUSE Linux Enterprise Server 12 SP5 LTSS Extended Security
    zypper in -t patch SUSE-SLE-SERVER-12-SP5-LTSS-EXTENDED-SECURITY-2025-3698=1

Package List:

  • SUSE Linux Enterprise Server 12 SP5 LTSS Extended Security (x86_64)
    • krb5-1.16.3-46.21.1
    • krb5-devel-1.16.3-46.21.1
    • krb5-plugin-kdb-ldap-1.16.3-46.21.1
    • krb5-plugin-preauth-otp-debuginfo-1.16.3-46.21.1
    • krb5-plugin-preauth-pkinit-debuginfo-1.16.3-46.21.1
    • krb5-client-debuginfo-1.16.3-46.21.1
    • krb5-doc-1.16.3-46.21.1
    • krb5-plugin-kdb-ldap-debuginfo-1.16.3-46.21.1
    • krb5-plugin-preauth-pkinit-1.16.3-46.21.1
    • krb5-server-1.16.3-46.21.1
    • krb5-debuginfo-1.16.3-46.21.1
    • krb5-debugsource-1.16.3-46.21.1
    • krb5-server-debuginfo-1.16.3-46.21.1
    • krb5-plugin-preauth-otp-1.16.3-46.21.1
    • krb5-client-1.16.3-46.21.1
    • krb5-debuginfo-32bit-1.16.3-46.21.1
    • krb5-32bit-1.16.3-46.21.1

References: