CVE-2012-0206 in PowerDNS
Summary
by MITRE
common_startup.cc in PowerDNS (aka pdns) Authoritative Server before 2.9.22.5 and 3.x before 3.0.1 allows remote attackers to cause a denial of service (packet loop) via a crafted UDP DNS response.
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Analysis
by VulDB Data Team • 11/30/2021
The vulnerability identified as CVE-2012-0206 affects PowerDNS authoritative server versions prior to 2.9.22.5 and 3.x before 3.0.1, representing a critical denial of service weakness in DNS infrastructure software. This flaw resides within the common_startup.cc component of the PowerDNS implementation, specifically in how the system processes incoming UDP DNS responses. The vulnerability enables remote attackers to manipulate the server's packet handling mechanisms through the injection of specially crafted UDP responses that trigger an infinite packet loop condition.
The technical root cause of this vulnerability stems from inadequate input validation and packet processing logic within the authoritative DNS server's response handling code. When the PowerDNS server receives a malformed UDP DNS response containing specific packet structures, the system fails to properly validate the response content before processing it within its internal packet loop mechanisms. This deficiency allows attackers to construct responses that cause the server to continuously process and reprocess the same packet sequence, creating an infinite loop that consumes system resources and ultimately leads to service disruption.
The operational impact of CVE-2012-0206 extends beyond simple service interruption to encompass significant infrastructure reliability concerns for organizations relying on PowerDNS authoritative servers. The packet loop condition can rapidly exhaust CPU cycles, memory resources, and network bandwidth, effectively rendering the affected DNS server incapable of processing legitimate queries. This vulnerability directly maps to CWE-400, which catalogs "Uncontrolled Resource Consumption" as a fundamental weakness in software systems, particularly when network input is not properly validated. The attack vector requires only remote access to send malicious UDP responses, making it particularly dangerous as it can be exploited from anywhere on the internet without requiring authentication or privileged access.
Organizations utilizing PowerDNS authoritative servers must implement immediate mitigations to address this vulnerability, with the most effective approach being the deployment of patched software versions that contain proper input validation and packet loop prevention mechanisms. The remediation strategy should include updating to PowerDNS versions 2.9.22.5 or 3.0.1 and later, which incorporate defensive programming practices that validate incoming packet structures before processing. Network-level mitigations such as implementing rate limiting on UDP traffic and deploying intrusion detection systems to monitor for anomalous packet patterns can provide additional protection layers. From an ATT&CK framework perspective, this vulnerability aligns with techniques related to resource exhaustion and denial of service attacks, specifically targeting the network infrastructure components that maintain DNS service availability. Organizations should also consider implementing proper network segmentation to limit the scope of potential impact and establish monitoring protocols to detect unusual packet processing behavior that might indicate exploitation attempts.