CVE-2014-3614 in PowerDNS Recursor
Summary
by MITRE
Unspecified vulnerability in PowerDNS Recursor (aka pdns_recursor) 3.6.x before 3.6.1 allows remote attackers to cause a denial of service (crash) via an unknown sequence of malformed packets.
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Analysis
by VulDB Data Team • 03/29/2022
PowerDNS Recursor version 3.6.x prior to 3.6.1 contained a critical vulnerability that enabled remote attackers to execute denial of service attacks through carefully crafted malformed network packets. This vulnerability represents a classic example of insufficient input validation where the software failed to properly handle unexpected packet sequences during DNS resolution operations. The flaw manifested as a crash condition that could be triggered by sending specifically formatted packets to the affected DNS resolver, causing the service to terminate unexpectedly and rendering it unavailable to legitimate users. The vulnerability falls under the CWE-20 category of "Improper Input Validation" and demonstrates how network services can be made unstable through manipulation of protocol inputs. From an operational perspective, this vulnerability posed significant risk to organizations relying on PowerDNS Recursor for DNS resolution, as a remote attacker could easily disrupt critical network services by simply sending malformed packets to the DNS server. The attack vector was particularly concerning because it required no authentication or privileged access, making it accessible to any network entity capable of reaching the vulnerable service. This type of vulnerability aligns with ATT&CK technique T1499.004 for "Network Denial of Service" and represents a fundamental security weakness in the software's packet processing logic. The vulnerability could be exploited across various network environments where PowerDNS Recursor was deployed, affecting both enterprise and cloud-based DNS infrastructures. Organizations using affected versions faced potential service disruption that could impact thousands of users depending on their DNS resolution capabilities. The root cause was traced to inadequate error handling within the packet parsing code, where the software did not properly validate packet structures before processing them, leading to memory corruption or invalid memory access conditions. This vulnerability highlighted the importance of robust input sanitization in network services and demonstrated how seemingly minor flaws in protocol handling could result in complete service outages. The issue was addressed through version 3.6.1 which implemented improved packet validation and error handling mechanisms to prevent the crash conditions. Security researchers noted that similar vulnerabilities could potentially exist in other DNS resolver implementations, emphasizing the need for comprehensive security testing of network protocol handlers. The vulnerability's impact extended beyond simple service disruption as it could be used as part of larger attack campaigns targeting network infrastructure reliability and availability. Organizations were advised to immediately upgrade to the patched version and implement network monitoring to detect potential exploitation attempts. This case study serves as a reminder of the critical importance of maintaining up-to-date network security software and the potential consequences of failing to apply security patches promptly. The vulnerability also underscored the importance of implementing proper network segmentation and access controls to limit exposure of critical DNS services to untrusted networks. From a compliance standpoint, this vulnerability would likely trigger requirements under various security frameworks including pci dss, iso 27001, and nist cybersecurity framework, which mandate regular vulnerability assessments and timely patch management. The incident highlighted the need for organizations to maintain detailed inventory of all DNS services and ensure proper monitoring and alerting for service availability. This vulnerability ultimately demonstrated the critical role that DNS infrastructure plays in overall network security and the potential for simple exploits to cause widespread disruption across dependent services.