CVE-2021-30465

Publication date 19 May 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

runc before 1.0.0-rc95 allows a Container Filesystem Breakout via Directory Traversal. To exploit the vulnerability, an attacker must be able to create multiple containers with a fairly specific mount configuration. The problem occurs via a symlink-exchange attack that relies on a race condition.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
runc	22.04 LTS jammy	Fixed 1.0.0~rc93-0ubuntu2
	21.10 impish	Fixed 1.0.0~rc93-0ubuntu2
	21.04 hirsute	Fixed 1.0.0~rc93-0ubuntu1.1
	20.10 groovy	Fixed 1.0.0~rc93-0ubuntu1~20.10.2
	20.04 LTS focal	Fixed 1.0.0~rc93-0ubuntu1~20.04.2
	18.04 LTS bionic	Fixed 1.0.0~rc93-0ubuntu1~18.04.2
	16.04 LTS xenial	Fixed 1.0.0~rc7+git20190403.029124da-0ubuntu1~16.04.4+esm2
	14.04 LTS trusty	Not in release

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Notes

mdeslaur

1.0.0-rc94 is also affected

Severity score breakdown

Parameter	Value
Base score	8.5 · High
Attack vector	Network
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Changed
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H