CVE-1999-0835 in BIND
Summary
by MITRE
Denial of service in BIND named via malformed SIG records.
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Analysis
by VulDB Data Team • 10/22/2025
The vulnerability identified as CVE-1999-0835 represents a critical denial of service weakness within the Berkeley Internet Name Domain (BIND) DNS server software. This issue specifically affects the named daemon responsible for handling DNS queries and responses within the BIND implementation. The vulnerability stems from inadequate validation of SIG (Signature) resource records that are part of the DNS Security Extensions (DNSSEC) framework. When the named daemon encounters malformed SIG records in DNS responses or queries, it fails to properly process these records, leading to system instability and potential service disruption. The flaw exists at the protocol parsing layer where the software does not adequately sanitize input data before attempting to interpret DNS signature information.
The technical exploitation of this vulnerability occurs when an attacker crafts specially malformed SIG records that trigger memory corruption or infinite loop conditions within the named process. These malformed records can be delivered through various attack vectors including DNS cache poisoning attempts or direct manipulation of DNS response packets. The vulnerability specifically impacts the DNS server's ability to process legitimate DNS queries and responses, causing the named daemon to crash or enter an unrecoverable state. According to CWE classification, this represents a weakness in input validation where insufficient checks are performed on DNS resource record data, particularly signature records that are part of the DNSSEC standard. The flaw demonstrates a classic buffer over-read or parsing error condition that can be exploited to cause system-wide denial of service.
The operational impact of CVE-1999-0835 extends beyond simple service interruption as it affects the fundamental reliability of DNS infrastructure. Organizations relying on affected BIND versions experience complete loss of DNS resolution capabilities until the named daemon is manually restarted or the system is rebooted. This vulnerability particularly affects critical network infrastructure components including primary and secondary DNS servers, authoritative name servers, and recursive resolvers. The attack surface is significant since DNS servers are typically accessible from external networks and often serve as foundational infrastructure for internet connectivity. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique involving network denial of service, where adversaries can leverage DNS server weaknesses to disrupt network communications and potentially gain access to other network resources.
Mitigation strategies for this vulnerability require immediate patching of affected BIND software versions, with administrators prioritizing updates to BIND 8.2.3 and later releases that contain proper input validation for SIG records. Network administrators should implement DNS server hardening measures including limiting external access to DNS services, implementing proper access controls, and monitoring for unusual DNS traffic patterns that might indicate exploitation attempts. Additional defensive measures include deploying DNS server clustering and failover mechanisms to ensure service availability during potential exploitation events. Organizations should also consider implementing DNS traffic filtering rules that can detect and block malformed SIG records before they reach the named daemon. The vulnerability highlights the importance of proper input validation in network services and demonstrates how seemingly minor protocol parsing flaws can result in complete service disruption. Security teams must also establish monitoring protocols to detect DNS server crashes or restarts that could indicate exploitation of this vulnerability, as the denial of service impact can be severe for organizations relying on DNS infrastructure for their network operations.