CVE-2006-0527 in BIND
Summary
by MITRE
BIND 4 (BIND4) and BIND 8 (BIND8), if used as a target forwarder, allows remote attackers to gain privileged access via a "Kashpureff-style DNS cache corruption" attack.
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Analysis
by VulDB Data Team • 06/13/2019
The vulnerability identified as CVE-2006-0527 represents a critical security flaw in Internet Systems Consortium BIND software versions 4 and 8, specifically when these versions function as target forwarders in DNS infrastructure. This issue stems from a sophisticated cache corruption attack vector that enables remote adversaries to escalate privileges and potentially gain unauthorized access to systems. The vulnerability operates through what is known as a "Kashpureff-style DNS cache corruption" technique, named after the researcher who first documented similar attack patterns in DNS security contexts.
The technical implementation of this vulnerability exploits fundamental weaknesses in how BIND4 and BIND8 handle DNS query responses when functioning as forwarders. When these servers receive DNS responses from upstream authoritative servers, they do not properly validate the source of the response or verify that the response corresponds to the original query being forwarded. This lack of proper validation creates opportunities for attackers to inject malicious DNS records into the cache, potentially redirecting traffic to attacker-controlled systems. The flaw specifically manifests when the forwarder receives a response that appears legitimate but contains crafted data designed to manipulate the caching mechanism.
From an operational perspective, the impact of this vulnerability extends far beyond simple cache corruption. Attackers exploiting this flaw can potentially redirect network traffic, compromise domain name resolution, and establish persistent access points within targeted networks. The privilege escalation aspect means that successful exploitation could allow attackers to gain administrative access to DNS servers, which serve as critical infrastructure components in most network environments. This makes the vulnerability particularly dangerous as DNS servers often operate with elevated privileges and serve as central points of control for network traffic routing.
The security implications of CVE-2006-0527 align with several cybersecurity frameworks and attack patterns documented in the MITRE ATT&CK framework, particularly in the areas of privilege escalation and credential access. The vulnerability also relates to CWE-20, which describes improper input validation, and CWE-1107, which covers improper neutralization of special elements used in DNS queries. Organizations relying on older BIND versions face significant risk exposure, as these systems may be targeted by sophisticated adversaries seeking to establish persistent network footholds through DNS infrastructure manipulation.
Mitigation strategies for this vulnerability require immediate patching of affected BIND versions, with priority given to upgrading to supported versions of BIND that contain proper input validation and response verification mechanisms. Network administrators should implement additional security controls including DNS query response validation, rate limiting of DNS queries, and monitoring for anomalous DNS traffic patterns. The recommended approach involves transitioning away from vulnerable BIND4 and BIND8 versions to modern BIND releases that incorporate robust security measures against cache poisoning attacks, including proper response validation and secure DNS implementation practices. Organizations should also consider implementing DNS security extensions such as DNSSEC to provide additional layers of protection against these types of attacks.