Permissions, Privileges, and Access Controls in containerd (Alpine package)

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU22482

Risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-16884

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

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to incorrect checking of the mount targets in libcontainer/rootfs_linux.go in runc. A local user can bypass AppArmor restrictions and perform unauthorized actions on the system, as demonstrated by overwriting the /proc directory with a malicious Doker image.

Mitigation

Install update from vendor's website.

Vulnerable software versions

containerd (Alpine package): 1.0.0-r0 - 1.3.4-r1

CPE2.3

• cpe:2.3:a:alpine:containerd_alpine_package:1.0.0-r0:*:*:*:*:alpine_linux:*:3.7
• cpe:2.3:a:alpine:containerd_alpine_package:1.0.0-r1:*:*:*:*:alpine_linux:*:3.8
• cpe:2.3:a:alpine:containerd_alpine_package:1.2.9-r0:*:*:*:*:alpine_linux:*:3.10

External links

https://git.alpinelinux.org/aports/commit/?id=c64d2552678a7126d5e1d18ac54ea0ee126298d9
https://git.alpinelinux.org/aports/commit/?id=76ff73346d335f4b22bc7ec01966172596ac8910
https://git.alpinelinux.org/aports/commit/?id=ca936aa88735c8b55f9745593fe8ce90f29bee9a
https://git.alpinelinux.org/aports/commit/?id=ac079d292f5197ccddd8cd79682f39fb96414415
https://git.alpinelinux.org/aports/commit/?id=c0c491116c2f9214f63040dbcdfc9f84de3e26a2

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.