CVE-2016-6318

Publication date 7 September 2016

Last updated 26 August 2025

Ubuntu priority

Negligible

Why this priority?

Cvss 3 Severity Score

7.8 · High

Score breakdown

Description

Stack-based buffer overflow in the FascistGecosUser function in lib/fascist.c in cracklib allows local users to cause a denial of service (application crash) or gain privileges via a long GECOS field, involving longbuffer.

Read the notes from the security team

Status

Package Ubuntu Release Status
cracklib2 25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
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
Vulnerable
14.04 LTS trusty
Vulnerable
12.04 LTS precise Ignored end of life

Notes

tyhicks

Ubuntu's chfn limits the total GECOS field length to 84 characters which is well within cracklib2's buffer size of 2048. libpam-cracklib is not part of the default install so PAM cracklib support is not enabled in the majority of Ubuntu installs Ubuntu's /etc/login.defs only allows unprivileged users to set their room number, work phone, and home phone

Patch details

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

Package Patch details
cracklib2

Severity score breakdown

Parameter Value
Base score 7.8 · High
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Other references