CVE-2016-6866

Publication date 15 February 2017

Last updated 25 August 2025

Ubuntu priority

Why this priority?

Cvss 3 Severity Score

Score breakdown

Description

slock allows attackers to bypass the screen lock via vectors involving an invalid password hash, which triggers a NULL pointer dereference and crash.

From the Ubuntu Security Team

It was discovered that slock incorrectly handled password hashes. An attacker could possibly use this issue to cause a denial of service.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
suckless-tools	18.10 cosmic	Not affected
	18.04 LTS bionic	Not affected
	17.10 artful	Ignored end of life
	17.04 zesty	Ignored end of life
	16.10 yakkety	Ignored end of life
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Fixed 40-1+deb8u2build0.14.04.1
	12.04 LTS precise	Ignored end of life

Notes

ratliff

for xenial and yakkety, the user must both disable pam and enable slock to be vulnerable

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Other references