Path traversal in libmspack

1) Path traversal

EUVDB-ID: #VU32031

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-18586

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

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

CPE2.3

• cpe:2.3:a:stuart_caie:libmspack:0.0.20060920alpha:*:*:*:*:*:*:
• cpe:2.3:a:stuart_caie:libmspack:0.3alpha:*:*:*:*:*:*:
• cpe:2.3:a:stuart_caie:libmspack:0.3:*:*:*:*:*:*:

External links

http://bugs.debian.org/911639
http://github.com/kyz/libmspack/commit/7cadd489698be117c47efcadd742651594429e6d
http://security.gentoo.org/glsa/201903-20
http://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.