CVE-2003-1473 in Ltris
Summary
by MITRE
Buffer overflow in LTris 1.0.1 of FreeBSD Ports Collection 2003-02-25 and earlier allows local users to execute arbitrary code with gid "games" permission via a long HOME environment variable.
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Analysis
by VulDB Data Team • 08/18/2024
The vulnerability identified as CVE-2003-1473 represents a critical buffer overflow flaw within LTris 1.0.1, a tetris game implementation distributed through the FreeBSD Ports Collection. This specific version of LTris was affected by a software defect that occurred when processing environment variables, particularly the HOME variable, during program execution. The vulnerability exists in the context of Unix-like operating systems where applications may improperly handle user-supplied input through environmental variables, creating opportunities for privilege escalation attacks. The flaw specifically targets systems where the LTris application is installed with setgid permissions to the games group, which is a common security practice for games and entertainment applications in Unix environments.
The technical nature of this buffer overflow stems from improper input validation within the LTris application's handling of the HOME environment variable. When a user launches the application with an excessively long HOME variable, the program fails to properly bounds-check the input before copying it into a fixed-size buffer. This classic programming error, classified under CWE-121 as "Stack-based Buffer Overflow", occurs because the application does not validate the length of the environment variable against the allocated buffer space. The buffer overflow allows an attacker to overwrite adjacent memory locations, potentially corrupting the program's execution flow and enabling code injection attacks. The vulnerability specifically leverages the setgid permission model where the application runs with elevated privileges, allowing local users to exploit this weakness to gain additional system access.
The operational impact of CVE-2003-1473 is significant for systems running affected versions of LTris, particularly in multi-user environments where the games group permission model is in use. Local users who can manipulate environment variables can exploit this vulnerability to execute arbitrary code with the privileges of the games group, which may include access to system resources, potential privilege escalation to other user groups, and the ability to compromise system integrity. The attack vector is relatively straightforward as it requires only local access and the ability to set environment variables, making it particularly dangerous in shared computing environments. This vulnerability aligns with ATT&CK technique T1068, which describes "Exploitation for Privilege Escalation" and specifically targets the exploitation of setuid/setgid binaries to gain elevated privileges.
Mitigation strategies for this vulnerability should focus on immediate remediation through system updates, as the FreeBSD Ports Collection would have released patched versions addressing the buffer overflow issue. System administrators should ensure all instances of LTris are updated to versions that properly validate input lengths before buffer operations. Additionally, security practices should include monitoring for unauthorized modifications to setgid applications and implementing proper environment variable sanitization. The vulnerability demonstrates the importance of input validation and proper buffer management in application development, reinforcing principles from the CERT/CC secure coding guidelines. Organizations should also consider implementing privilege separation techniques and ensuring that applications with elevated permissions undergo thorough security auditing to prevent similar issues in the future. The remediation process should include verifying that no other applications in the system suffer from similar buffer overflow vulnerabilities through comprehensive vulnerability scanning and code review processes.