CVE-2000-1029 in BIND
Summary
by MITRE
Buffer overflow in host command allows a remote attacker to execute arbitrary commands via a long response to an AXFR query.
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Analysis
by VulDB Data Team • 01/27/2025
The vulnerability described in CVE-2000-1029 represents a critical buffer overflow flaw within the host command implementation that specifically affects DNS zone transfer operations. This vulnerability resides in the handling of AXFR (Authoritative Zone Transfer) queries which are fundamental components of DNS server communication protocols. The host command, which is commonly used for DNS lookups and zone transfers, fails to properly validate the length of responses received during authoritative zone transfers, creating an exploitable condition that can be leveraged by remote attackers.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the DNS client-side tool. When the host command processes an AXFR response, it does not enforce strict bounds checking on the size of incoming data, allowing attackers to craft malicious responses that exceed the allocated buffer space. This buffer overflow condition occurs during the processing of DNS zone transfer data where the program attempts to store more information than the allocated memory buffer can accommodate. The flaw specifically manifests when the host command receives a malformed AXFR response containing an excessive amount of data, causing the program to overwrite adjacent memory locations and potentially execute arbitrary code.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it enables remote code execution capabilities for attackers who can successfully exploit the buffer overflow condition. An attacker positioned to intercept or manipulate DNS traffic can craft malicious AXFR responses that, when processed by vulnerable host command implementations, result in arbitrary command execution on the target system. This represents a significant security risk because DNS tools are often used in administrative contexts and may run with elevated privileges, potentially allowing attackers to gain unauthorized access to systems. The vulnerability affects systems that utilize the host command for DNS resolution and zone transfer operations, particularly those running older versions of DNS software implementations.
Mitigation strategies for this vulnerability require immediate patching of affected DNS software implementations and the application of security updates provided by vendors. System administrators should implement network segmentation and access controls to limit exposure to potentially malicious DNS traffic, while also considering the deployment of DNS security measures such as DNSSEC to protect against data manipulation. Network monitoring should be enhanced to detect anomalous DNS traffic patterns that might indicate exploitation attempts, and the principle of least privilege should be enforced when running DNS client tools. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and represents a classic example of how improper input validation can lead to remote code execution. The attack pattern associated with this vulnerability follows the ATT&CK technique T1071.004 for DNS tunneling and T1059 for command and scripting interpreter, making it a significant concern for organizations implementing comprehensive threat detection strategies. Organizations should also consider implementing intrusion detection systems that can identify and block malformed DNS responses that exceed expected data size parameters.