#VU30624 Link following in crun - CVE-2019-18837

Vulnerability identifier: #VU30624

Vulnerability 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

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
crun
Other software / Other software solutions

Vendor: Container Projects

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 update from vendor's website.

Vulnerable software versions

crun: 0.10.3 - 0.10.4

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External links
https://github.com/containers/crun/pull/173
https://github.com/containers/crun/releases/tag/0.10.5
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DTA5SJUAKQUK6HRY2CZVJUIZP5BO3EOG/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ITB2UNEGHXZUR3ATYHWPSK5LJB36N7AP/

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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.