CVE-2004-2300 in ucd-snmp
Summary
by MITRE
Buffer overflow in snmpd in ucd-snmp 4.2.6 and earlier, when installed setuid root, allows local users to execute arbitrary code via a long -p command line argument. NOTE: it is not clear whether there are any standard configurations in which snmpd is installed setuid or setgid. If not, then this issue should not be included in CVE.
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Analysis
by VulDB Data Team • 06/25/2018
The vulnerability described in CVE-2004-2300 represents a critical buffer overflow condition within the snmpd daemon component of ucd-snmp version 4.2.6 and earlier. This issue manifests when the snmpd service is executed with elevated privileges through setuid root permissions, creating a dangerous attack vector for local adversaries. The buffer overflow occurs specifically during processing of command line arguments, particularly when a lengthy -p parameter is provided to the snmpd daemon. This flaw falls under the CWE-121 category of Stack-based Buffer Overflow, where insufficient bounds checking allows an attacker to overwrite adjacent memory locations. The vulnerability demonstrates the classic risk of privilege escalation through insecure input handling in setuid applications, where the elevated privileges of the running process can be exploited to execute arbitrary code with root-level permissions.
The operational impact of this vulnerability extends beyond simple code execution, as it enables full system compromise when exploited successfully. Attackers can leverage this buffer overflow to overwrite critical memory segments including return addresses, function pointers, or other control data structures within the snmpd process memory space. This enables malicious code injection that can subsequently spawn shellcode or establish persistent backdoors within the target system. The attack requires local system access but provides root-level privileges, making it particularly dangerous for environments where snmpd is configured with setuid root permissions. According to ATT&CK framework, this vulnerability maps to T1068 (Local Privilege Escalation) and T1059 (Command and Scripting Interpreter) techniques, as it allows attackers to execute arbitrary commands with elevated privileges through the compromised snmpd process.
The technical exploitation of this vulnerability hinges on the specific configuration where snmpd runs with setuid root permissions, which creates an inherent security risk. Standard SNMP configurations typically do not require snmpd to operate with elevated privileges, as the daemon can function adequately with standard user permissions while maintaining proper network access controls. The vulnerability exists because the command line argument parsing routine lacks proper input validation and boundary checking for the -p parameter, which is commonly used to specify the port number or other daemon configuration options. When an attacker provides an excessively long argument string, the fixed-size buffer allocated for processing this parameter overflows into adjacent memory, potentially corrupting the program's execution flow. This type of vulnerability is classified as CWE-125, Out-of-bounds Read, and CWE-787, Out-of-bounds Write, depending on the specific memory corruption pattern during exploitation.
Mitigation strategies for CVE-2004-2300 focus on both immediate remediation and long-term architectural improvements to prevent similar issues. The primary recommendation involves updating to ucd-snmp versions 4.2.7 or later, where the buffer overflow has been patched through proper input validation and bounds checking. Organizations should also review their SNMP daemon configurations to ensure that snmpd is not running with unnecessary setuid root permissions, as this practice inherently increases attack surface and risk exposure. Security hardening measures include implementing proper privilege separation, where the daemon drops root privileges immediately upon startup, and utilizing proper input sanitization for all command line arguments. Additionally, system administrators should conduct regular audits of setuid/setgid binaries and implement mandatory access controls through mechanisms such as SELinux or AppArmor to limit the potential damage from such privilege escalation vulnerabilities. The vulnerability highlights the importance of following secure coding practices and adhering to the principle of least privilege in system administration.