Security restrictions bypass in PolicyKit

1) Security restrictions bypass

EUVDB-ID: #VU16966

Risk: Low

CVSSv3.1: 6.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:U/RC:C]

CVE-ID: CVE-2019-6133

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The vulnerability exists due to fork() is not atomic, and therefore authorization decisions are improperly cached, related to lack of uid checking in polkitbackend/polkitbackendinteractiveauthority.c. A remote unauthenticated attacker can bypass the "start time" protection mechanism

Mitigation

Cybersecurity Help is currently unaware of any official solution to address the vulnerability.

Vulnerable software versions

PolicyKit: 0.115

External links

http://gitlab.freedesktop.org/polkit/polkit/merge_requests/19
http://bugs.chromium.org/p/project-zero/issues/detail?id=1692

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.