CVE-2016-4459 in mod_cluster
Summary
by MITRE
Stack-based buffer overflow in native/mod_manager/node.c in mod_cluster 1.2.9.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability CVE-2016-4459 represents a critical stack-based buffer overflow flaw discovered in the mod_cluster module version 1.2.9, specifically within the native/mod_manager/node.c source file. This issue affects the Apache HTTP Server module that provides load balancing and clustering capabilities for application servers. The buffer overflow occurs when processing certain input data structures, creating a potential exploitation vector that could allow remote attackers to execute arbitrary code on affected systems. The vulnerability is particularly concerning as it resides in the core management component responsible for handling cluster node communications and status updates.
The technical implementation of this flaw stems from improper input validation and boundary checking within the node management functions of mod_cluster. When the module processes incoming data from cluster nodes, it fails to adequately validate the size of input buffers before copying data onto the stack. This allows an attacker to provide malicious input that exceeds the allocated buffer space, causing a stack overflow condition that can overwrite adjacent memory locations including return addresses and control data. The vulnerability manifests in the way the module handles node status information and communication protocols, making it exploitable through carefully crafted cluster management requests.
From an operational impact perspective, this vulnerability creates significant security risks for organizations relying on mod_cluster for load balancing and application deployment. Attackers who successfully exploit this buffer overflow could gain arbitrary code execution privileges on the affected Apache server, potentially leading to full system compromise. The attack surface extends beyond simple code execution to include potential privilege escalation and lateral movement within network environments. Organizations using mod_cluster in production environments face elevated risk of unauthorized access, data breaches, and service disruption, particularly in scenarios where the affected servers are exposed to untrusted network traffic or where cluster management interfaces are accessible from external networks.
Mitigation strategies for CVE-2016-4459 should prioritize immediate patching of affected mod_cluster installations to version 1.3.0 or later, which contains the necessary fixes for the buffer overflow vulnerability. System administrators should also implement network segmentation and access controls to limit exposure of cluster management interfaces to trusted networks only. Additional defensive measures include monitoring for suspicious cluster communication patterns, implementing intrusion detection systems to identify potential exploitation attempts, and conducting thorough security assessments of all mod_cluster deployments. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is categorized under the broader category of CWE-119 Improper Access of Resources, and maps to ATT&CK technique T1059 Command and Scripting Interpreter for executing malicious code through compromised systems. Organizations should also consider implementing application whitelisting policies and regular security updates to prevent similar vulnerabilities from being exploited in their infrastructure.