Fedora 31 update for crun

1) Link following

EUVDB-ID: #VU30624

Risk: High

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2019-18837

CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

An issue was discovered in crun before 0.10.5. With a crafted image, it doesn't correctly check whether a target is a symlink, resulting in access to files outside of the container. This occurs in libcrun/linux.c and libcrun/chroot_realpath.c.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 31

crun: before 0.10.5-2.fc31

CPE2.3

• cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
• cpe:2.3:a:fedoraproject:crun:*:*:*:*:*:fedora:*:*

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2019-1ba2a6e386

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.