Privilege escalation in Flatpak

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU59654

Risk: Medium

CVSSv3.1: 6.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-43860

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, which leads to security restrictions bypass and privilege escalation.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Flatpak: 1.8.0 - 1.12.2

External links

http://github.com/flatpak/flatpak/commit/d9a8f9d8ccc0b7c1135d0ecde006a75d25f66aee
http://github.com/flatpak/flatpak/commit/65cbfac982cb1c83993a9e19aa424daee8e9f042
http://github.com/flatpak/flatpak/commit/93357d357119093804df05acc32ff335839c6451
http://github.com/flatpak/flatpak/commit/ba818f504c926baaf6e362be8159cfacf994310e
http://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j
http://github.com/flatpak/flatpak/commit/54ec1a482dfc668127eaae57f135e6a8e0bc52da
http://github.com/flatpak/flatpak/releases/tag/1.12.3
http://github.com/flatpak/flatpak/releases/tag/1.10.6
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/APFTBYGJJVJPFVHRXUW5PII5XOAFI4KH/
http://github.com/flatpak/flatpak/releases/tag/1.8.7

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.