CVE-2016-3120

Publication date 1 August 2016

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.5 · Medium

Score breakdown

Description

The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.

From the Ubuntu Security Team

It was discovered that Kerberos incorrectly handled certain data structures. A remote authenticated attacker could possibly use this issue to cause a denial of service.

Read the notes from the security team

Status

Package Ubuntu Release Status
krb5 21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
17.10 artful
Not affected
17.04 zesty
Not affected
16.10 yakkety
Not affected
16.04 LTS xenial
Fixed 1.13.2+dfsg-5ubuntu2.1
15.10 wily Ignored end of life
14.04 LTS trusty
Fixed 1.12+dfsg-2ubuntu5.4
12.04 LTS precise Ignored end of life

Notes

ratliff

KDC is not supported for core and touch

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
krb5

Severity score breakdown

Parameter Value
Base score 6.5 · Medium
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Other references