Denial of service in Info-ZIP UnZip

1) Input validation error

EUVDB-ID: #VU18051

Risk: Medium

CVSSv3.1: 6.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:P/RL:U/RC:C]

CVE-ID: CVE-2016-9844

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in the zi_short() function in zipinfo.c when processing a large compression method value in the central directory file header. A remote attacker can pass a specially crafted array to the application and trigger denial of service (DoS) condition.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

UnZip: 6.0

External links

http://www.openwall.com/lists/oss-security/2016/12/05/13
http://www.openwall.com/lists/oss-security/2016/12/05/19
http://www.openwall.com/lists/oss-security/2016/12/05/20
http://www.securityfocus.com/bid/94728
http://bugs.launchpad.net/ubuntu/+source/unzip/+bug/1643750

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted archive.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.