Multiple vulnerabilities in accountsservice (Ubuntu package)

Published: 2020-11-11

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2020-16127 CVE-2020-16126
CWE-ID	CWE-835 CWE-264
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available.
Vulnerable software Subscribe	accountsservice (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Infinite loop

EUVDB-ID: #VU48379

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-16127

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: Yes

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

accountsservice (Ubuntu package): 0.6.1-1 - 0.6.55-0ubuntu12~20.04.1

External links

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

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU48380