CVE-2016-2054 in Xymon
Summary
by MITRE
Multiple buffer overflows in xymond/xymond.c in xymond in Xymon 4.1.x, 4.2.x, and 4.3.x before 4.3.25 allow remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a long filename, involving handling a "config" command.
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Analysis
by VulDB Data Team • 07/24/2022
The vulnerability identified as CVE-2016-2054 represents a critical buffer overflow flaw in the xymond daemon component of the Xymon monitoring system. This issue affects versions 4.1.x through 4.3.x prior to the security patch release of 4.3.25, creating a significant attack surface for remote adversaries seeking to compromise monitoring infrastructure. The vulnerability specifically manifests when the xymond daemon processes a "config" command with an excessively long filename parameter, allowing attackers to manipulate memory layout and potentially execute arbitrary code on affected systems.
The technical exploitation of this vulnerability stems from inadequate input validation and bounds checking within the xymond.c source file where the daemon handles configuration commands. When processing a malformed filename exceeding predetermined buffer limits, the system fails to properly truncate or reject excessive input, leading to memory corruption that can result in stack smashing or heap corruption patterns. This type of flaw directly aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations, and may also relate to CWE-787, representing out-of-bounds writes that can occur when input validation is insufficient.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full system compromise capabilities for remote attackers. A successful exploitation could enable attackers to execute malicious code with the privileges of the xymond daemon process, potentially leading to complete system takeover or persistent backdoor establishment. The daemon crash resulting from buffer overflows represents a denial of service vector that could disrupt critical monitoring infrastructure, potentially masking actual security incidents or creating windows of opportunity for further attacks. Given that xymond typically operates as a core monitoring component in network infrastructure, this vulnerability could severely impact operational continuity and security posture.
Mitigation strategies for CVE-2016-2054 should prioritize immediate patching to version 4.3.25 or later, which includes proper input validation and buffer size enforcement for filename handling. Network administrators should implement additional monitoring to detect anomalous command patterns or unusually long filename parameters that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter execution, as exploitation would likely involve command injection patterns. System hardening measures including input sanitization, privilege separation for daemon processes, and regular security audits of monitoring infrastructure should be implemented to reduce the attack surface and prevent similar vulnerabilities from emerging in other components of the Xymon suite or related monitoring systems.