Improper access control in containerd (Alpine package)

1) Improper access control

EUVDB-ID: #VU48795

Risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15257

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: Yes

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 update from vendor's website.

Vulnerable software versions

containerd (Alpine package): 1.4.2-r0

docker (Alpine package): 19.03.13-r0

CPE2.3

• cpe:2.3:o:alpine:containerd_alpine_package:1.4.2-r0:*:*:*:*:alpine_linux:*:
• cpe:2.3:o:alpine:docker_alpine_package:19.03.13-r0:*:*:*:*:alpine_linux:*:

External links

http://git.alpinelinux.org/aports/commit/?id=c613502998289a1f8402c04c7f88b6c46ad8206e
http://git.alpinelinux.org/aports/commit/?id=0a37a11ae1d1bfbd09ea8ff208327a3c689862b4

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.