CVE-2012-3534 in GNU Gatekeeper
Summary
by MITRE
GNU Gatekeeper before 3.1 does not limit the number of connections to the status port, which allows remote attackers to cause a denial of service (connection and thread consumption) via a large number of connections.
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Analysis
by VulDB Data Team • 12/12/2021
The vulnerability identified as CVE-2012-3534 affects GNU Gatekeeper versions prior to 3.1, presenting a critical security flaw in the software's connection handling mechanism for its status port. This issue stems from the absence of connection rate limiting or throttling controls that would normally prevent excessive simultaneous connections to the system's monitoring interface. The status port serves as a critical management endpoint that provides system information and operational metrics, making it a valuable target for attackers seeking to disrupt service availability. The flaw represents a classic resource exhaustion attack vector where malicious actors can exploit the lack of connection limits to consume system resources and degrade performance.
The technical implementation of this vulnerability lies in the software's failure to enforce connection rate limiting or maximum connection thresholds for the status port functionality. When remote attackers establish numerous concurrent connections to this port, the system's thread management and connection handling mechanisms become overwhelmed, leading to resource depletion. Each connection consumes system resources including memory, file descriptors, and thread contexts that are finite and must be managed efficiently. Without proper bounds on concurrent connections, legitimate users and system processes may be denied access to the status port, while the system itself experiences performance degradation or complete unresponsiveness. This behavior aligns with the common pattern of denial of service attacks targeting resource exhaustion as outlined in the attack pattern taxonomy.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader system stability and availability concerns. When the status port becomes overwhelmed with connections, administrators lose visibility into system operations, making troubleshooting and monitoring ineffective. The resource consumption affects not only the status port functionality but can also impact the overall system performance, potentially causing cascading failures in dependent services. This vulnerability particularly affects systems where GNU Gatekeeper serves as a critical component for VoIP or telephony services, where monitoring and status information are essential for maintaining service quality and operational integrity. The attack vector requires minimal technical expertise and can be executed using readily available network tools, making it a significant concern for organizations running vulnerable versions of the software.
Mitigation strategies for CVE-2012-3534 should focus on immediate version upgrades to GNU Gatekeeper 3.1 or later, which includes proper connection limiting mechanisms. Network-level protections such as firewall rules can be implemented to restrict access to the status port, limiting connections to trusted management networks only. Additionally, implementing connection rate limiting at the operating system level or through dedicated network appliances can provide an additional layer of defense. System administrators should also consider implementing monitoring solutions that can detect unusual connection patterns to the status port and trigger automated alerts or connection limiting measures. The vulnerability demonstrates the importance of proper resource management and access control in security architecture, aligning with common security practices outlined in the CWE database under categories related to resource exhaustion and access control failures. Organizations should conduct thorough vulnerability assessments to identify all instances of vulnerable GNU Gatekeeper installations and implement comprehensive patch management procedures to prevent exploitation.