Vulnerability identifier: #VU48795

Vulnerability risk: Medium

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

CVE-ID: CVE-2020-15257

CWE-ID: CWE-284

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
containerd
Other software / Other software solutions

Vendor: containerd

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions. Access controls for the shim’s API socket verified that the connecting process had an effective UID of 0, but did not otherwise restrict access to the abstract Unix domain socket. This would allow malicious containers running in the same network namespace as the shim, with an effective UID of 0 but otherwise reduced privileges, to cause new processes to be run with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

containerd: 1.3.0 - 1.3.8, 1.4.0 - 1.4.2

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External links
http://github.com/containerd/containerd/commit/4a4bb851f5da563ff6e68a83dc837c7699c469ad
http://github.com/containerd/containerd/releases/tag/v1.4.3
http://github.com/containerd/containerd/security/advisories/GHSA-36xw-fx78-c5r4

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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. However, proof of concept for this vulnerability is available.