CVE-2017-3139 in BIND
Summary
by MITRE
A denial of service flaw was found in the way BIND handled DNSSEC validation. A remote attacker could use this flaw to make named exit unexpectedly with an assertion failure via a specially crafted DNS response.
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Analysis
by VulDB Data Team • 09/24/2020
The vulnerability identified as CVE-2017-3139 represents a critical denial of service weakness within the Berkeley Internet Name Domain (BIND) software implementation. This flaw specifically impacts the DNSSEC validation process, which is fundamental to ensuring the authenticity and integrity of DNS responses in the internet infrastructure. The issue manifests when BIND encounters specially crafted DNS responses that trigger an assertion failure, causing the named process to terminate unexpectedly and disrupting DNS resolution services for affected systems.
The technical root cause of this vulnerability lies in BIND's insufficient input validation during DNSSEC validation operations. When processing DNS responses that contain malformed or crafted DNSSEC records, the software fails to properly handle edge cases in the validation logic, leading to assertion failures that result in process termination. This behavior stems from inadequate error handling mechanisms within the DNSSEC validation code path, where the software assumes certain data structures will maintain expected formats and values. The flaw operates at the application layer of the network stack, specifically targeting the named daemon that serves as the primary DNS server implementation in many internet-facing systems.
The operational impact of CVE-2017-3139 extends beyond simple service disruption, as it can be exploited by remote attackers to systematically compromise DNS services across affected networks. This vulnerability directly affects the availability of DNS resolution services, potentially causing cascading failures in internet infrastructure that depends on stable DNS operations. The attack vector requires minimal privileges and can be executed against any system running vulnerable versions of BIND, making it particularly dangerous for internet service providers, enterprise networks, and any organization relying on DNS for critical infrastructure operations. The assertion failure mechanism means that successful exploitation results in immediate process termination without graceful shutdown procedures, potentially leading to incomplete DNS cache states and further service instability.
Organizations affected by this vulnerability should implement immediate mitigations including updating to patched versions of BIND that address the assertion failure conditions in DNSSEC validation. The fix typically involves strengthening input validation routines and adding proper error handling for malformed DNSSEC records. System administrators should also consider implementing network-level protections such as DNS response filtering and monitoring for anomalous DNS traffic patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-617, which describes reachable assertions in software systems, and maps to ATT&CK technique T1499.004 for network disruption attacks targeting DNS services. Organizations should also review their DNSSEC configuration practices and consider implementing additional monitoring and alerting mechanisms to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of robust input validation and error handling in security-critical network infrastructure software, particularly when dealing with cryptographic validation processes that must handle diverse and potentially malicious inputs from untrusted sources.