Main Vulnerability Database Vulnerabilities #VU48379

Infinite loop in accountsservice (Ubuntu package) - CVE-2020-16127

Published: November 11, 2020 / Updated: November 12, 2020

Vulnerability identifier: #VU48379

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-16127

CWE-ID: CWE-835

Exploitation vector: Local access

Exploit availability: Public exploit is available

Vulnerability details

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to infinite loop in the "is_in_pam_environment" function. A local user can trigger an infinite loop by creating a symlink to "/dev/zero" and cause denial of service conditions.

Affected software

accountsservice (Ubuntu package)

How to mitigate CVE-2020-16127

Install updates from vendor's website.

accountsservice (Ubuntu package) - update to 0.6.55-0ubuntu13.2

Links to Public Exploits and PoC-codes

Exploit #4835 - Ubuntu-Gnome-privilege-escalation (A bash script exploit of [CVE-2020-16126/CVE-2020-16127] to achieve privilege escalation.Ubuntu 16.04-20.04 LTS本地提权漏洞利用脚本。要求拥有Gnome图形化环境。) (November 12, 2020)

External References

https://securitylab.github.com/advisories/GHSL-2020-187-accountsservice-drop-privs-DOS

Related Security Bulletins

Multiple vulnerabilities in accountsservice (Ubuntu package)