CVE-2007-3112 in Cacti
Summary
by MITRE
graph_image.php in Cacti 0.8.6i, and possibly other versions, allows remote authenticated users to cause a denial of service (CPU consumption) via a large value of the (1) graph_start or (2) graph_end parameter, different vectors than CVE-2007-3113.
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Analysis
by VulDB Data Team • 07/30/2019
The vulnerability described in CVE-2007-3112 affects Cacti version 0.8.6i and potentially other versions, targeting the graph_image.php component within the monitoring system. This issue represents a denial of service vulnerability that can be exploited by authenticated remote attackers who manipulate specific parameters in the web interface. The flaw manifests when attackers submit excessively large values for either the graph_start or graph_end parameters, which causes the system to consume excessive CPU resources during graph rendering operations. This vulnerability operates through a different attack vector compared to CVE-2007-3113, which suggests that multiple variants of similar flaws exist within the same software version.
The technical implementation of this vulnerability stems from inadequate input validation and parameter sanitization within the graph_image.php script. When legitimate users attempt to generate graphs with extremely large time range values, the system fails to properly validate these inputs before processing them. The absence of proper bounds checking allows attackers to submit values that force the application to perform intensive computations or iterate through excessive data ranges. This leads to sustained high CPU utilization as the system attempts to render graphs with parameters that would normally be rejected or automatically adjusted by proper validation mechanisms.
The operational impact of this vulnerability extends beyond simple service disruption, as it can effectively render the monitoring system unusable for legitimate users. Attackers can maintain sustained denial of service conditions by submitting carefully crafted large values that keep system resources consumed for extended periods. The vulnerability affects the availability aspect of the CIA triad, specifically targeting the system's ability to provide continuous monitoring services. Network administrators may find their monitoring infrastructure becomes unresponsive or severely degraded, potentially masking actual network issues that Cacti was designed to detect and report.
From a cybersecurity perspective, this vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of a resource exhaustion attack pattern that can be mapped to ATT&CK technique T1499.3 for network denial of service. The authentication requirement suggests that attackers must first establish valid credentials, potentially through credential compromise or social engineering, before executing the attack. Organizations should consider implementing parameter validation controls, setting reasonable limits on input ranges, and monitoring for unusual CPU consumption patterns that might indicate exploitation attempts.
Effective mitigation strategies include applying the vendor-provided security patches, implementing input validation controls that limit parameter ranges, and configuring rate limiting mechanisms to prevent excessive requests from single authenticated users. System administrators should also establish monitoring protocols that can detect abnormal CPU usage patterns and automatically alert security teams to potential exploitation attempts. The vulnerability demonstrates the importance of proper input sanitization in web applications and highlights the need for comprehensive security testing that includes boundary condition validation and resource consumption analysis. Organizations utilizing Cacti or similar monitoring systems should conduct thorough security assessments to identify and remediate similar vulnerabilities that might exist in their monitoring infrastructure.