CVE-2019-18634

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.

Recent assessments:

SherlockSec at March 09, 2020 8:43pm UTC reported:

This exploit is similar to CVE-2019-14287, in that it requires a specific config within /etc/sudoers. Present in sudo versions < 1.8.26, this vuln surrounds the pwfeedback option: an option that allows sudo to display asteriks when typing a sudo password. This module is susceptible to a buffer overflow attack, which was demonstrated in the following PoC:

$ perl -e 'print(("A" x 100 . "\x{00}") x 50)' | sudo -S id
    Password: Segmentation fault

_Source – <https://www.exploit-db.com/exploits/47995&gt;_

An exploit for this vuln can be found here – <https://github.com/saleemrashid/sudo-cve-2019-18634&gt;

A preconfigured test environment can be found here – <https://tryhackme.com/room/sudovulnsbof&gt;

wvu-r7 at February 03, 2020 7:40am UTC reported:

This exploit is similar to CVE-2019-14287, in that it requires a specific config within /etc/sudoers. Present in sudo versions < 1.8.26, this vuln surrounds the pwfeedback option: an option that allows sudo to display asteriks when typing a sudo password. This module is susceptible to a buffer overflow attack, which was demonstrated in the following PoC:

$ perl -e 'print(("A" x 100 . "\x{00}") x 50)' | sudo -S id
    Password: Segmentation fault

_Source – <https://www.exploit-db.com/exploits/47995&gt;_

An exploit for this vuln can be found here – <https://github.com/saleemrashid/sudo-cve-2019-18634&gt;

A preconfigured test environment can be found here – <https://tryhackme.com/room/sudovulnsbof&gt;

Assessed Attacker Value: 2
Assessed Attacker Value: 2Assessed Attacker Value: 5