Denial of service in libmspack

1) Null pointer dereference

EUVDB-ID: #VU15908

Risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-18585

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to  the chmd_read_headers function, as defined in the mspack/chmd.c source code file of the affected software, accepts filenames that have embedded NULL bytes. A remote attacker can trick the victim into accessing a Compiled HTML (CHM) file that submits malicious input to the targeted system, trigger NULL pointer dereference and cause the service to crash.

Mitigation

Update to version 0.8alpha.

Vulnerable software versions

libmspack: 0.3 - 0.7

External links

http://github.com/kyz/libmspack/commit/8759da8db6ec9e866cb8eb143313f397f925bb4f

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.