CVE-2014-2031 in Deadwood
Summary
by MITRE
Deadwood before 2.3.09, 3.x before 3.2.05, and as used in MaraDNS before 1.4.14 and 2.x before 2.0.09, allow remote attackers to cause a denial of service (out-of-bounds read and crash) by leveraging permission to perform recursive queries against Deadwood, related to a logic error.
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Analysis
by VulDB Data Team • 02/05/2021
The vulnerability identified as CVE-2014-2031 affects the Deadwood DNS resolver implementation and its integration within MaraDNS software versions. This issue represents a critical security flaw that allows remote attackers to execute denial of service attacks through carefully crafted recursive DNS queries. The vulnerability stems from a logic error within the DNS resolution process that occurs when Deadwood handles recursive query requests, creating conditions that lead to out-of-bounds memory reads and subsequent application crashes.
The technical flaw manifests as an improper handling of DNS query processing logic where the Deadwood resolver fails to properly validate or bounds-check data structures during recursive query execution. When legitimate users with permission to perform recursive queries submit specially crafted DNS requests, the application's internal state management becomes corrupted, leading to memory access violations. This particular vulnerability falls under CWE-129, which describes improper validation of array indices, and more specifically relates to CWE-787, out-of-bounds write operations that can be triggered by improper input validation. The flaw exists in multiple versions of Deadwood and MaraDNS, indicating a systemic issue within the codebase that affects both version 2.x and 3.x series of the software.
The operational impact of this vulnerability extends beyond simple service disruption as it can be exploited by remote attackers without requiring authentication or elevated privileges. Any entity with access to perform recursive DNS queries against affected systems can trigger the out-of-bounds read condition, causing the Deadwood resolver process to crash and terminate unexpectedly. This results in immediate denial of service for legitimate DNS resolution requests, potentially affecting numerous network services that depend on proper DNS functionality. The vulnerability is particularly concerning because it can be exploited through standard DNS traffic without requiring specialized tools or privileged access, making it a high-risk issue for any organization relying on these DNS resolution services.
Mitigation strategies for CVE-2014-2031 involve immediate software updates to patched versions of Deadwood and MaraDNS, specifically versions 2.0.09, 1.4.14, 3.2.05, and 2.3.09 respectively. Organizations should implement network segmentation to restrict recursive query permissions to trusted sources only, reducing the attack surface available to potential adversaries. Additionally, monitoring systems should be deployed to detect unusual DNS query patterns that may indicate exploitation attempts, while implementing rate limiting on recursive query processing can help prevent abuse. From an ATT&CK framework perspective, this vulnerability maps to technique T1499.004 which covers network denial of service attacks, and the exploitation process aligns with T1071.004 for application layer protocol usage. The remediation approach should include comprehensive testing of updated software in staging environments before deployment to production systems, ensuring that the patch resolves the vulnerability without introducing regressions in DNS resolution functionality.