#VU32031 Path traversal in libmspack - CVE-2018-18586

Vulnerability identifier: #VU32031

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-18586

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libmspack
Universal components / Libraries / Libraries used by multiple products

Vendor: Stuart Caie

Description

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

** DISPUTED ** chmextract.c in the chmextract sample program, as distributed with libmspack before 0.8alpha, does not protect against absolute/relative pathnames in CHM files, leading to Directory Traversal. NOTE: the vendor disputes that this is a libmspack vulnerability, because chmextract.c was only intended as a source-code example, not a supported application.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libmspack: 0.0.20060920alpha - 0.7.1alpha

---

External links
https://bugs.debian.org/911639
https://github.com/kyz/libmspack/commit/7cadd489698be117c47efcadd742651594429e6d
https://security.gentoo.org/glsa/201903-20
https://www.openwall.com/lists/oss-security/2018/10/22/1

---

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.