Fedora 29 update for runc

1) Privilege escalation

EUVDB-ID: #VU17474

Risk: Medium

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

CVE-ID: CVE-2019-5736

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

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain elevated privileges.

The weakness exists in the runc container runtime due to file-descriptor mishandling, related to /proc/self/exe. A remote attacker can leverage the ability to execute a command as root within one of these types of containers: (1) a new container with an attacker-controlled image, or (2) an existing container, to which the attacker previously had write access, that can be attached with docker exec, overwrite the host runc binary with minimal user interaction and execute arbitrary code with root privileges.

Successful exploitation of the vulnerability may result in system compromise.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 29

runc: before 1.0.0-92.dev.gitc1b8c57.fc29

CPE2.3

• cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
• cpe:2.3:a:fedoraproject:runc:*:*:*:*:*:fedora:*:*

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2019-6174b47003

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, a fully functional exploit for this vulnerability is available.