CVE-2002-0651 in BIND
Summary
by MITRE
Buffer overflow in the DNS resolver code used in libc, glibc, and libbind, as derived from ISC BIND, allows remote malicious DNS servers to cause a denial of service and possibly execute arbitrary code via the stub resolvers.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability described in CVE-2002-0651 represents a critical buffer overflow flaw within the DNS resolver implementations found in core system libraries including libc, glibc, and libbind. This issue stems from the ISC BIND software foundation and affects systems that utilize stub resolvers for DNS query processing. The vulnerability manifests when these libraries process DNS responses from malicious servers, creating a potential attack vector that can be exploited by remote adversaries. The buffer overflow occurs during the parsing of DNS packet responses, specifically when handling oversized or malformed DNS data structures that exceed the allocated buffer space. This flaw impacts the fundamental network resolution capabilities of affected systems and can be leveraged to disrupt normal operations or potentially gain unauthorized execution privileges.
The technical implementation of this vulnerability resides in the DNS resolver code's insufficient input validation and buffer management practices. When stub resolvers receive DNS responses, they typically allocate fixed-size buffers to store the response data and process it according to the DNS protocol specifications. However, the flawed implementation fails to properly validate the size of incoming DNS data, particularly in the handling of resource record data and domain name compression mechanisms. This allows attackers to craft specially crafted DNS responses that contain data exceeding the allocated buffer boundaries. The overflow can overwrite adjacent memory locations including return addresses, function pointers, or other critical control data structures, leading to unpredictable behavior. According to CWE classification, this represents a classic buffer overflow vulnerability (CWE-121) that can be categorized as a stack-based buffer overflow when the vulnerability affects stack-allocated buffers during function execution.
The operational impact of CVE-2002-0651 extends beyond simple denial of service scenarios to encompass potential remote code execution capabilities. When exploited successfully, attackers can manipulate the program flow through stack corruption, potentially allowing them to execute arbitrary code with the privileges of the affected process. The vulnerability affects systems that rely on the standard DNS resolution libraries, which includes virtually all Unix-like operating systems and applications that depend on libc or glibc for network operations. This creates a widespread attack surface since many network services and applications utilize these libraries for name resolution. The impact is particularly severe in environments where systems are configured to use recursive DNS resolution or where applications perform extensive DNS lookups. The vulnerability can be exploited through various attack vectors including malicious DNS servers, compromised DNS infrastructure, or man-in-the-middle attacks that intercept DNS traffic.
Mitigation strategies for this vulnerability require immediate patching of affected systems and implementation of network-level protections. System administrators should prioritize updating their libc, glibc, and libbind packages to versions that contain the necessary buffer overflow fixes and input validation improvements. The patches typically implement proper bounds checking on DNS response data and ensure that buffer allocations accommodate the maximum possible DNS packet sizes according to RFC specifications. Network administrators should consider implementing DNS filtering mechanisms and monitoring for suspicious DNS traffic patterns that may indicate exploitation attempts. Additionally, implementing DNS security measures such as DNSSEC validation can help prevent certain types of attacks by ensuring the authenticity of DNS responses. From an ATT&CK framework perspective, this vulnerability maps to multiple techniques including T1071.004 (Application Layer Protocol: DNS) for the initial attack vector and T1059.007 (Command and Scripting Interpreter: PowerShell) for potential exploitation methods, though the primary attack surface remains in the network protocol handling and memory corruption domains. Organizations should also implement proper system hardening measures including address space layout randomization (ASLR) and stack canaries to reduce the effectiveness of exploitation attempts.