#VU25847 Improper access control in runc - CVE-2019-19921

Vulnerability identifier: #VU25847

Vulnerability risk: Low

CVSSv4.0: 7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2019-19921

CWE-ID: CWE-284

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
runc
Client/Desktop applications / Other client software

Vendor: Open Container Initiative

Description

The vulnerability allows a local user to gain unauthorized access to sensitive information.

The vulnerability exists due to improper access restrictions, related to libcontainer/rootfs_linux.go in runc. A local user with ability to spawn two containers with custom volume-mount configurations, and run custom images can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

runc: 1.0.0 rc1 - 1.0.0 rc9

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External links
https://lists.opensuse.org/opensuse-security-announce/2020-02/msg00018.html
https://github.com/opencontainers/runc/issues/2197
https://github.com/opencontainers/runc/pull/2190
https://github.com/opencontainers/runc/releases
https://security-tracker.debian.org/tracker/CVE-2019-19921

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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.