CVE-2019-12522

Publication date 15 April 2020

Last updated 3 October 2025

Ubuntu priority

Cvss 3 Severity Score

Description

An issue was discovered in Squid through 4.7. When Squid is run as root, it spawns its child processes as a lesser user, by default the user nobody. This is done via the leave_suid call. leave_suid leaves the Saved UID as 0. This makes it trivial for an attacker who has compromised the child process to escalate their privileges back to root.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
squid	25.10 questing	Vulnerable, fix deferred
	25.04 plucky	Vulnerable, fix deferred
	24.10 oracular	Ignored end of life, was deferred
	24.04 LTS noble	Vulnerable, fix deferred
	23.10 mantic	Ignored end of life, was deferred
	23.04 lunar	Ignored end of life, was deferred
	22.10 kinetic	Ignored end of life, was deferred
	22.04 LTS jammy	Vulnerable, fix deferred
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Vulnerable, fix deferred
	19.10 eoan	Ignored end of life
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
squid3	25.10 questing	Not in release
	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	21.10 impish	Not in release
	21.04 hirsute	Not in release
	20.10 groovy	Not in release
	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Vulnerable, fix deferred
	16.04 LTS xenial	Vulnerable, fix deferred
	14.04 LTS trusty	Not in release

Notes

mdeslaur

as of 2025-10-03, there is no fix from upstream for this issue

Severity score breakdown

Parameter	Value
Base score	4.5 · Medium
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	Low
Availability impact	Low
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L