CVE-2017-7401 in collectd
Summary
by MITRE
Incorrect interaction of the parse_packet() and parse_part_sign_sha256() functions in network.c in collectd 5.7.1 and earlier allows remote attackers to cause a denial of service (infinite loop) of a collectd instance (configured with "SecurityLevel None" and with empty "AuthFile" options) via a crafted UDP packet.
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Analysis
by VulDB Data Team • 08/24/2024
The vulnerability identified as CVE-2017-7401 represents a critical denial of service flaw within the collectd monitoring daemon version 5.7.1 and earlier. This issue stems from a problematic interaction between two core parsing functions within the network.c source file, specifically parse_packet() and parse_part_sign_sha256(). The collective impact of this flaw allows remote attackers to induce an infinite loop condition in the affected collectd service, ultimately leading to complete service unavailability. The vulnerability manifests when collectd instances are configured with SecurityLevel set to "None" and the AuthFile option left empty, creating an exploitable configuration state that bypasses normal authentication mechanisms.
The technical root cause of this vulnerability lies in the improper validation and handling of crafted UDP packets within the packet parsing logic. When the parse_packet() function processes incoming network data, it invokes parse_part_sign_sha256() to validate signature components. However, under specific conditions involving malformed packet structures, the interaction between these functions creates a logical error that results in an infinite loop. This occurs because the parsing logic fails to properly validate the boundaries and structure of signature data, causing the loop to continue indefinitely without proper termination conditions. The flaw is particularly dangerous because it operates at the network protocol level, allowing attackers to exploit it through standard network traffic without requiring authentication or elevated privileges.
The operational impact of CVE-2017-7401 extends beyond simple service disruption, as it can effectively瘫痪 entire monitoring infrastructures that rely on collectd for system metrics collection. Organizations using collectd in environments where SecurityLevel is configured to "None" and no authentication files are specified face significant risk of sustained denial of service attacks. This vulnerability aligns with CWE-835, which addresses infinite loops in software systems, and represents a classic example of how improper input validation can lead to resource exhaustion attacks. The attack vector is particularly concerning as it operates over UDP protocol, making it difficult to trace and block at network levels, and can be executed by any remote attacker with access to the network.
From a cybersecurity perspective, this vulnerability demonstrates the importance of proper input validation and defensive programming practices in network services. The flaw can be exploited through the ATT&CK framework's privilege escalation and denial of service tactics, specifically targeting the service availability component of the attack lifecycle. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous for organizations with insufficient network segmentation or monitoring capabilities. Organizations should immediately consider implementing network-level restrictions to limit UDP traffic to collectd ports, while also applying the vendor-provided patches to address the underlying parsing logic errors. The issue underscores the necessity of maintaining up-to-date security configurations and the importance of avoiding insecure default settings such as SecurityLevel None in production environments.