Vulnerability identifier: #VU24922

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-5209

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
NetHack
Client/Desktop applications / Games

Vendor: The NetHack DevTeam

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when unknown options starting with -de and -i. A remote attacker can trigger memory corruption and cause a denial of service (DoS) condition or execute arbitrary code on the target system with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note: This vulnerability affects systems that have NetHack installed suid/sgid and shared systems that allow users to influence command line options.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

NetHack: 3.2.3 - 3.6.4

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External links
http://github.com/NetHack/NetHack/commit/f3def5c0b999478da2d0a8f0b6a7c370a2065f77
http://github.com/NetHack/NetHack/security/advisories/GHSA-fw72-r8xm-45p8
http://nethack.org/security/CVE-2020-5209.html

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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.