CVE-2009-4112 in Cacti
Summary
by MITRE
Cacti 0.8.7e and earlier allows remote authenticated administrators to gain privileges by modifying the "Data Input Method" for the "Linux - Get Memory Usage" setting to contain arbitrary commands.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/23/2025
The vulnerability identified as CVE-2009-4112 affects Cacti versions 0.8.7e and earlier, representing a critical privilege escalation flaw that enables authenticated administrators to execute arbitrary commands on the affected system. This vulnerability specifically targets the Data Input Method configuration within Cacti's monitoring framework, which is designed to collect and process system metrics from various sources. The flaw arises from insufficient input validation and sanitization mechanisms within the application's administrative interface, particularly when handling the configuration of data input methods for system monitoring.
The technical exploitation of this vulnerability occurs through a command injection attack vector where an authenticated administrator can modify the "Linux - Get Memory Usage" Data Input Method setting to include malicious command sequences. When Cacti processes this modified configuration, it executes the injected commands with the privileges of the web application user, typically running with elevated system permissions. This represents a classic command injection vulnerability classified under CWE-77, which occurs when a web application incorporates user-supplied data into system commands without proper sanitization. The vulnerability exists because the application fails to properly validate or escape special characters that could be interpreted as command delimiters or operators by the underlying operating system shell.
The operational impact of this vulnerability is severe as it allows attackers with administrative credentials to escalate their privileges and execute arbitrary code on the target system. Once exploited, the attacker gains access to the system's command execution environment and can potentially establish persistent backdoors, exfiltrate sensitive data, or compromise other systems within the network. The vulnerability affects organizations that rely on Cacti for network monitoring and system performance tracking, as it provides a pathway for attackers to move laterally within their infrastructure. This type of vulnerability is particularly dangerous because it requires minimal privileges to exploit and can be leveraged to achieve full system compromise, making it a prime target for attackers seeking to establish persistent access within monitored environments.
Mitigation strategies for this vulnerability include immediate patching of Cacti installations to versions 0.8.7f or later where the vulnerability has been addressed through proper input validation and sanitization of user-supplied data. Organizations should implement the principle of least privilege by restricting administrative access to only necessary personnel and employing multi-factor authentication for administrative accounts. Network segmentation and monitoring of administrative activities can help detect unauthorized modifications to critical system configurations. Additionally, implementing web application firewalls and input validation controls can provide defense-in-depth measures against similar command injection vulnerabilities. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1484.001 for domain policy modification, demonstrating how privilege escalation can be leveraged to modify system configurations and establish persistent access within monitored environments. Regular security assessments and code reviews focusing on input validation and sanitization practices are essential for preventing similar vulnerabilities in other applications within the organization's infrastructure.