CVE-2016-6318

Publication date 7 September 2016

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

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

Show unmaintained releases

Package	Ubuntu Release	Status
cracklib2	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	Upstream: https://bugzilla.redhat.com/attachment.cgi?id=1188599

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