CVE-2006-1390 in Linux
Summary
by MITRE
The configuration of NetHack 3.4.3-r1 and earlier, Falcon s Eye 1.9.4a and earlier, and Slash EM 0.0.760 and earlier on Gentoo Linux allows local users in the games group to modify saved games files to execute arbitrary code via buffer overflows and overwrite arbitrary files via symlink attacks.
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Analysis
by VulDB Data Team • 06/16/2019
The vulnerability identified as CVE-2006-1390 affects multiple roguelike games including NetHack, Falcon s Eye, and Slash EM versions prior to their respective updates on Gentoo Linux systems. This issue stems from improper handling of saved game files within the gaming environment, creating a pathway for local privilege escalation through maliciously crafted file modifications. The affected software packages are commonly installed with group permissions that allow users within the games group to interact with game data files, establishing a potential attack vector that leverages both buffer overflow conditions and symbolic link manipulation techniques.
The technical flaw manifests through buffer overflow vulnerabilities that occur when the games process handles saved game files containing maliciously crafted input data. These buffer overflows can be exploited by local users who have membership in the games group to overwrite arbitrary files on the system through symlink attacks. The vulnerability is particularly concerning because it allows an attacker to execute arbitrary code with the privileges of the game process, which typically runs with elevated permissions to manage game state and save files. The exploitation requires the attacker to have local access and membership in the games group, but the impact can be severe as it bypasses normal file system protections and can lead to complete system compromise.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to modify critical system files, potentially creating persistent backdoors or escalating privileges to root access. The attack vector combines multiple exploitation techniques including buffer overflows that can be triggered during game save operations and symbolic link manipulation that allows file overwrite operations. This dual approach makes the vulnerability particularly dangerous in environments where games are frequently played and saved, as the attack surface remains active during normal usage patterns. The vulnerability affects systems where these games are installed with setuid or setgid permissions, allowing the games to maintain elevated privileges while operating within the games group context.
Mitigation strategies should focus on immediate patching of affected software versions to address the buffer overflow conditions and implement proper file access controls to prevent symlink attacks. System administrators should ensure that games are updated to versions that properly validate input data and handle file operations securely without requiring elevated privileges. The implementation of proper file permissions and access controls can prevent users from creating symbolic links that could be exploited to overwrite critical system files. Additionally, monitoring for unusual file access patterns and implementing sandboxing techniques for game execution can help detect and prevent exploitation attempts. This vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflows and improper access control, and represents a typical attack pattern classified under ATT&CK technique T1068 for local privilege escalation through process manipulation. The vulnerability demonstrates the importance of proper input validation and file handling in multi-user systems where different privilege levels interact with shared resources.