CVE-2017-16820 in collectd
Summary
by MITRE
The csnmp_read_table function in snmp.c in the SNMP plugin in collectd before 5.6.3 is susceptible to a double free in a certain error case, which could lead to a crash (or potentially have other impact).
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-16820 represents a critical memory corruption flaw within the SNMP plugin of the collectd monitoring system. This issue affects versions prior to 5.6.3 and specifically targets the csnmp_read_table function located in the snmp.c file. The vulnerability manifests as a double free condition that occurs during error handling scenarios within the SNMP table reading functionality, creating a potential vector for system instability and unauthorized code execution.
The technical implementation of this vulnerability stems from improper memory management within the SNMP plugin's error handling pathway. When the csnmp_read_table function encounters certain error conditions, it attempts to free memory resources that have already been freed previously, resulting in a double free scenario. This memory corruption pattern typically occurs when the function fails to properly track memory allocation states or when multiple code paths lead to the same memory deallocation operations. The flaw is categorized under CWE-415 as an improper handling of memory allocation and deallocation, specifically manifesting as double free conditions that can lead to arbitrary code execution or system crashes.
The operational impact of this vulnerability extends beyond simple system crashes to potentially enable more sophisticated attack vectors. An attacker who can trigger the specific error case that leads to the double free condition could potentially exploit this weakness to execute arbitrary code on the affected system. The vulnerability affects systems running collectd versions before 5.6.3, which are commonly used in network monitoring and system performance tracking environments, making them attractive targets for attackers seeking persistent access to monitoring infrastructure. The potential for remote code execution through this vulnerability places it within the ATT&CK framework's technique T1059.007 for command and control through remote access tools, as compromised monitoring systems could be used to establish persistent backdoors.
The remediation for this vulnerability requires immediate upgrading to collectd version 5.6.3 or later, which includes proper memory management fixes within the SNMP plugin. Organizations should also implement network segmentation and access controls around monitoring systems to limit potential exploitation vectors. Additionally, regular security assessments of monitoring infrastructure should include verification of plugin versions and proper memory handling practices. The vulnerability demonstrates the importance of thorough error handling in network monitoring tools, as these systems often run with elevated privileges and are critical to infrastructure security. Security teams should also consider implementing intrusion detection systems that monitor for unusual memory allocation patterns that might indicate exploitation attempts, as the double free condition could potentially be detected through anomalous system behavior rather than direct exploitation.