#VU22482 Permissions, Privileges, and Access Controls in runc - CVE-2019-16884

Vulnerability identifier: #VU22482

Vulnerability 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

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
runc
Server applications / Virtualization software

Vendor: Linux Foundation

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 updates from vendor's website.

Vulnerable software versions

runc: 1.0.0 rc1 - 1.0.0 rc8

---

External links
https://github.com/opencontainers/runc/issues/2128
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DGK6IV5JGVDXHOXEKJOJWKOVNZLT6MYR/

---

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.