CVE-2003-1084 in Monit
Summary
by MITRE
Monit 1.4 to 4.1 allows remote attackers to cause a denial of service (daemon crash) via an HTTP POST request with a negative Content-Length field.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability described in CVE-2003-1084 represents a classic buffer overflow and input validation flaw affecting the Monit monitoring daemon version 1.4 through 4.1. This issue stems from inadequate handling of HTTP protocol elements within the daemon's web interface implementation. The vulnerability specifically targets the Content-Length header field in HTTP POST requests, where a negative value can be submitted to exploit the daemon's parsing logic. This type of vulnerability falls under the category of improper input validation as defined by CWE-20, which is a fundamental weakness in software design that allows malicious input to disrupt normal application behavior.
The technical exploitation of this vulnerability occurs when a remote attacker crafts an HTTP POST request containing a negative Content-Length field value. The Monit daemon, upon receiving such a request, fails to properly validate the Content-Length parameter before attempting to process the incoming data. This improper validation leads to integer underflow or overflow conditions within the daemon's memory management routines, ultimately causing the daemon to crash and restart. The flaw demonstrates a clear lack of robust input sanitization and error handling mechanisms within the HTTP request processing pipeline. This vulnerability is particularly concerning because it can be exploited remotely without requiring authentication, making it a significant threat to system availability and service continuity.
The operational impact of this vulnerability extends beyond simple daemon crashes to potentially disrupt critical system monitoring functions. When the Monit daemon crashes, it ceases to monitor system processes, file integrity, and resource usage that administrators rely upon for maintaining system health. This creates a window of vulnerability where system administrators may be unaware of critical failures or security incidents occurring while the monitoring service is offline. The daemon crash also represents a denial of service condition that can be repeatedly exploited to maintain persistent availability issues, potentially allowing attackers to degrade system reliability over time. According to ATT&CK framework, this vulnerability maps to T1499.004 which covers network disruption and T1566.001 which involves phishing with malicious attachments, though the latter is more applicable to how the vulnerability might be delivered.
Mitigation strategies for CVE-2003-1084 should focus on both immediate patching and defensive configuration measures. The most effective solution involves upgrading to Monit versions beyond 4.1 where the vulnerability has been addressed through proper input validation and sanitization of HTTP headers. Organizations should also implement network-level protections such as firewall rules that restrict access to the Monit web interface to trusted IP addresses only. Additionally, implementing intrusion detection systems that can identify and alert on malformed HTTP requests containing negative Content-Length values provides an additional layer of defense. Configuration hardening should include disabling the web interface when not required and ensuring that only necessary services are exposed to external networks. The vulnerability highlights the importance of implementing proper input validation at multiple levels within applications and aligns with security best practices outlined in ISO/IEC 27001 and NIST SP 800-53 for secure software development and system hardening.