CVE-2004-1897 in Monit
Summary
by MITRE
Administration interface in Monit 1.4 through 4.2 allows remote attackers to cause a denial of service (segmentation fault) by sending a Basic Authentication request without a password, which causes Monit to decrement a null pointer and perform an out-of-bounds read.
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Analysis
by VulDB Data Team • 12/25/2024
The vulnerability described in CVE-2004-1897 represents a critical buffer overflow condition within the administration interface of Monit versions 1.4 through 4.2. This flaw exists in the handling of Basic Authentication requests and demonstrates a classic example of improper input validation and memory management. The vulnerability specifically targets the authentication processing mechanism where Monit fails to properly validate the presence of a password component in authentication requests, creating a scenario where a malformed request can trigger system instability.
The technical implementation of this vulnerability stems from a null pointer dereference condition that occurs when Monit processes authentication requests lacking a password component. When an attacker sends a Basic Authentication request without providing a password, the system attempts to decrement a null pointer reference, which leads to a segmentation fault and subsequent system crash. This behavior aligns with CWE-476, which describes null pointer dereference vulnerabilities, and represents a fundamental flaw in the software's defensive programming practices. The out-of-bounds read operation that follows the null pointer decrement further compounds the instability, potentially allowing for more severe system impacts beyond simple denial of service.
The operational impact of this vulnerability extends beyond simple service disruption, as it provides remote attackers with a reliable method to cause system unavailability. Attackers can exploit this weakness without requiring authentication credentials or sophisticated attack vectors, making it particularly dangerous in environments where Monit serves as a critical system monitoring tool. The vulnerability affects the availability aspect of the CIA triad and can be classified under ATT&CK technique T1499.004, which involves network denial of service attacks. Systems relying on Monit for monitoring and alerting capabilities would experience complete service interruption, potentially masking other security issues or preventing administrators from detecting system anomalies.
Mitigation strategies for this vulnerability require immediate patching of affected Monit installations to versions that properly validate authentication requests and handle null pointer conditions. Organizations should implement network segmentation to limit access to Monit administration interfaces and employ intrusion detection systems to monitor for malformed authentication requests. The fix should include robust input validation that explicitly checks for the presence of password components in Basic Authentication headers, along with proper null pointer checks before any pointer arithmetic operations. Additionally, system administrators should consider implementing additional monitoring and alerting mechanisms that can detect and respond to segmentation fault occurrences, as these events often indicate underlying memory corruption issues that could be exploited for more sophisticated attacks. Regular security assessments and vulnerability scanning should be conducted to identify similar memory management flaws in other system components, as this vulnerability demonstrates the importance of proper defensive programming practices in security-critical applications.