CVE-2019-18634 Sudo < 1.8.26

Vulnerable to stack-based BOf

Detail

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.

PoC

https://github.com/saleemrashid/sudo-cve-2019-18634

Detection

Affects sudo versions before 1.8.26.

pwfeedback is enabled in /etc/sudoers.

Mitigation

Upgrade sudo version.

References:

https://nvd.nist.gov/vuln/detail/CVE-2019-18634 https://www.sudo.ws/security/advisories/pwfeedback/