Path traversal in libmspack (Alpine package)

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 (Alpine package): 0.5_alpha-r0 - 0.8-r1

External links

http://git.alpinelinux.org/aports/commit/?id=3a49d88a9384e72b92ad518a7f8cf56dfe1c4513
http://git.alpinelinux.org/aports/commit/?id=6f862b5f45d6e18068d8e26af441f403f4444e6e
http://git.alpinelinux.org/aports/commit/?id=c9b4a96edd80dfc0ae4bd6d76202612f6bbd42d7
http://git.alpinelinux.org/aports/commit/?id=e59fb2371eb8b367558761b562b73e8b1935e498

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.