CVE-2011-2464 in BIND
Summary
by MITRE
Unspecified vulnerability in ISC BIND 9 9.6.x before 9.6-ESV-R4-P3, 9.7.x before 9.7.3-P3, and 9.8.x before 9.8.0-P4 allows remote attackers to cause a denial of service (named daemon crash) via a crafted UPDATE request.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability identified as CVE-2011-2464 represents a critical denial of service weakness affecting the Internet Systems Consortium BIND DNS server software. This issue specifically impacts versions 9.6.x prior to 9.6-ESV-R4-P3, 9.7.x prior to 9.7.3-P3, and 9.8.x prior to 9.8.0-P4, creating a significant risk for organizations relying on DNS infrastructure. The flaw manifests when the named daemon processes a specially crafted UPDATE request, leading to a complete crash of the DNS server process. This type of vulnerability falls under the category of improper input validation and can be classified as CWE-129, which encompasses issues related to insufficient validation of array indices. The vulnerability operates at the application layer of the network stack and represents a classic example of a resource exhaustion attack vector that can be exploited remotely without requiring authentication.
The technical exploitation of this vulnerability demonstrates a fundamental flaw in the UPDATE request processing mechanism within BIND's DNS server implementation. When a malicious actor sends a crafted UPDATE request to a vulnerable BIND server, the server's named daemon fails to properly validate or sanitize the incoming data structure. This failure results in an abnormal termination of the named process, effectively causing a denial of service condition that disrupts DNS resolution services for all clients relying on that server. The vulnerability is particularly concerning because it allows remote attackers to trigger a crash from any location on the internet, making it an attractive target for attackers seeking to disrupt network services. The attack vector operates through the DNS protocol's UPDATE functionality, which is designed to allow authorized clients to modify DNS records, but the implementation lacks proper bounds checking and input validation.
The operational impact of CVE-2011-2464 extends beyond simple service disruption to potentially affect broader network infrastructure reliability and availability. Organizations running vulnerable BIND versions face the risk of sustained denial of service attacks that can render their DNS services completely unavailable, impacting everything from internal network operations to external customer access. The vulnerability's remote exploitability means that attackers can target multiple servers simultaneously without requiring physical access or network proximity, making it particularly dangerous in large enterprise environments where DNS servers serve as critical infrastructure components. From an operational perspective, this vulnerability can lead to cascading failures as dependent services that rely on DNS resolution become unavailable, potentially affecting email services, web applications, and other network-dependent systems. The attack can be executed with minimal resources and technical expertise, making it a preferred method for both opportunistic and targeted attacks against network infrastructure.
Mitigation strategies for CVE-2011-2464 primarily focus on immediate software patching and configuration hardening measures. Organizations should prioritize upgrading to patched versions of BIND 9.6-ESV-R4-P3, 9.7.3-P3, or 9.8.0-P4 respectively, which contain the necessary fixes to prevent the malformed UPDATE requests from causing daemon crashes. Additionally, implementing network-level controls such as firewall rules that restrict UPDATE request processing to trusted sources can provide temporary protection while patches are deployed. The implementation of rate limiting mechanisms and monitoring for unusual UPDATE request patterns can help detect potential exploitation attempts. Security professionals should also consider disabling UPDATE functionality entirely if it is not required for their specific use cases, following the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to techniques involving service stoppage and denial of service, specifically targeting the DNS service availability aspect of network infrastructure. Organizations should also implement comprehensive monitoring solutions that can detect anomalous DNS traffic patterns and automatically alert security teams to potential exploitation attempts, as outlined in defensive strategies for maintaining network resilience against such attacks.