Vulnerability identifier: #VU822

Vulnerability risk: High

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a local user to obtain elevated privileges on the target system.

The vulnerability exists due to improper processing of symbolic links (symlinks) or hard links. By
 overwriting files outside of the libarchive extraction directory or modifying the directory permissions a mailicious user can obtain root privileges on the system.

Successful exploitation of this vulnerability will allow the local attacker to obtain elevated privileges on vulnerable system.

Mitigation
Update patched versions:
- 10.1 (https://security.FreeBSD.org/patches/SA-16:31/libarchive-10.1.patch);
- 10.2 (https://security.FreeBSD.org/patches/SA-16:31/libarchive-10.2.patch);
- 10.3 (https://security.FreeBSD.org/patches/SA-16:31/libarchive-10.3.patch).

Vulnerable software versions

FreeBSD: 5.3 - 11.0

---

External links
http://www.freebsd.org/security/advisories/FreeBSD-SA-16:31.libarchive.asc

---

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.