CVE-2020-5209 : Exploit Details and Defense Strategies

NetHack command line parsing of options starting with -de and -i is subject to a buffer overflow.

Understanding CVE-2020-5209

In NetHack before 3.6.5, unknown options starting with -de and -i can cause a buffer overflow resulting in a crash or remote code execution/privilege escalation.

What is CVE-2020-5209?

NetHack before version 3.6.5 is vulnerable to buffer overflow due to unknown options starting with -de and -i.
This vulnerability affects systems with NetHack installed suid/sgid and shared systems allowing user influence on command line options.

The Impact of CVE-2020-5209

CVSS Base Score: 5 (Medium)
Attack Vector: Local
Attack Complexity: High
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality, Integrity, and Availability Impact: Low

Technical Details of CVE-2020-5209

Vulnerability Description

The vulnerability arises from the mishandling of command line options in NetHack, leading to a buffer overflow.

Affected Systems and Versions

Affected Product: NetHack
Vendor: NetHack
Vulnerable Versions: < 3.6.5

Exploitation Mechanism

Attackers can exploit this vulnerability by providing malicious input through command line options, potentially leading to a crash or unauthorized code execution.

Mitigation and Prevention

Immediate Steps to Take

Upgrade NetHack to version 3.6.5 to mitigate the vulnerability.

Long-Term Security Practices

Avoid running NetHack with elevated privileges unless necessary.
Regularly monitor and restrict user access to command line options.

Patching and Updates

Stay informed about security advisories and promptly apply patches to address known vulnerabilities.