CVE-2019-18634

Publication date 31 January 2020

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

In Sudo before 1.8.26, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo process. (pwfeedback is a default setting in Linux Mint and elementary OS; however, it is NOT the default for upstream and many other packages, and would exist only if enabled by an administrator.) The attacker needs to deliver a long string to the stdin of getln() in tgetpass.c.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
sudo	19.10 eoan	Fixed 1.8.27-1ubuntu4.1
	18.04 LTS bionic	Fixed 1.8.21p2-3ubuntu1.2
	16.04 LTS xenial	Fixed 1.8.16-0ubuntu1.9
	14.04 LTS trusty	Fixed 1.8.9p5-1ubuntu1.5+esm3 Ubuntu Pro

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Notes

mdeslaur

pwfeedback is not enabled in Ubuntu affects 1.7.1 to 1.8.25p1 as it can't be exploited in 1.8.26 to 1.8.30

Patch details

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

Package	Patch details
sudo	Upstream: fa8ffeb

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