CVE-2011-0414 in BIND
Summary
by MITRE
ISC BIND 9.7.1 through 9.7.2-P3, when configured as an authoritative server, allows remote attackers to cause a denial of service (deadlock and daemon hang) by sending a query at the time of (1) an IXFR transfer or (2) a DDNS update.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability identified as CVE-2011-0414 affects Internet Systems Consortium BIND versions 9.7.1 through 9.7.2-P3 when configured as an authoritative DNS server. This issue represents a significant denial of service weakness that can be exploited by remote attackers to compromise the availability of DNS services. The vulnerability specifically targets the interaction between incoming DNS queries and ongoing authoritative server operations, creating a scenario where the DNS daemon becomes unresponsive and enters a deadlock state.
The technical flaw manifests when an attacker sends a specially crafted DNS query during critical operational periods such as incremental zone transfers or dynamic DNS updates. During these processes, the BIND server maintains internal locks and state information to ensure data consistency and proper transaction handling. The vulnerability occurs because the server's processing logic fails to properly handle concurrent access patterns between regular query processing and the zone transfer or DDNS update operations. This concurrency issue creates a deadlock condition where the server's main processing threads become blocked waiting for resources that are held by other threads in a circular dependency.
The operational impact of this vulnerability is severe as it can lead to complete service disruption for DNS clients relying on the affected server. When the daemon hangs due to the deadlock, all DNS queries submitted to the server will either time out or fail to resolve, effectively taking the DNS service offline. This denial of service condition can persist until the affected BIND process is manually restarted or the system is rebooted, making it particularly dangerous in production environments where high availability is critical. The vulnerability affects both IPv4 and IPv6 DNS operations and can be exploited by attackers without requiring authentication or special privileges.
From a cybersecurity perspective, this vulnerability aligns with CWE-362, which describes a race condition where two or more threads access shared resources concurrently, leading to unpredictable behavior. The issue also relates to ATT&CK technique T1499.004, which covers network denial of service attacks targeting DNS services. Organizations using affected BIND versions should prioritize immediate patching to address this vulnerability, as the attack surface is broad and the impact is substantial. The fix typically involves updating to BIND version 9.7.2-P4 or later, which includes proper synchronization mechanisms to prevent the deadlock conditions during concurrent operations. Additionally, network administrators should implement monitoring solutions to detect unusual patterns of DNS query traffic that might indicate exploitation attempts, and consider implementing rate limiting or access control measures to reduce the effectiveness of potential attacks.