CVE-2003-0914 in BIND
Summary
by MITRE
ISC BIND 8.3.x before 8.3.7, and 8.4.x before 8.4.3, allows remote attackers to poison the cache via a malicious name server that returns negative responses with a large TTL (time-to-live) value.
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Analysis
by VulDB Data Team • 07/20/2025
The vulnerability described in CVE-2003-0914 represents a significant cache poisoning flaw in ISC BIND DNS software versions 8.3.x prior to 8.3.7 and 8.4.x prior to 8.4.3. This issue stems from the improper handling of negative DNS responses with elevated time-to-live values, creating a pathway for remote attackers to manipulate DNS cache contents. The vulnerability operates within the fundamental DNS resolution process where authoritative servers provide negative responses indicating that a requested domain name does not exist, and these responses contain TTL values that dictate how long the response should be cached.
The technical flaw manifests when a malicious name server responds to DNS queries with negative responses that include unusually large TTL values, typically in the range of several hours or even days. When ISC BIND receives such responses, it processes them according to standard DNS caching behavior without adequately validating the legitimacy of the TTL values or the source of the negative response. This allows attackers to inject false information into the DNS cache that will persist for the duration specified by the malicious TTL value, effectively hijacking DNS resolution for the targeted domains.
The operational impact of this vulnerability extends beyond simple cache poisoning, as it can enable sophisticated attacks including DNS hijacking, man-in-the-middle attacks, and redirection of network traffic to malicious destinations. Attackers can exploit this weakness to redirect users to phishing sites, malware distribution points, or other malicious resources by poisoning the cache with false DNS records that appear legitimate due to their extended TTL values. The extended cache duration significantly amplifies the potential damage, as compromised cache entries remain effective for extended periods, making detection and remediation more challenging.
This vulnerability aligns with CWE-209, which describes improper handling of DNS cache poisoning attacks, and corresponds to techniques found in the MITRE ATT&CK framework under the T1071.004 sub-technique for DNS tunneling and cache poisoning. The issue demonstrates how seemingly minor protocol implementation flaws can create substantial security risks when combined with the inherent trust relationships within DNS infrastructure. Organizations running affected BIND versions face potential exposure to widespread DNS-based attacks that can compromise entire network domains, as the poisoned cache entries can affect all clients that rely on the compromised DNS server for resolution. The vulnerability underscores the critical importance of proper input validation and security hardening in DNS infrastructure components, particularly when handling responses from potentially untrusted sources.
Mitigation strategies for this vulnerability include immediate deployment of patched BIND versions 8.3.7 or 8.4.3, which implement enhanced validation of TTL values in negative responses. Administrators should also consider implementing DNS security extensions, configuring appropriate cache validation mechanisms, and monitoring DNS cache contents for suspicious entries. The fix addresses the root cause by introducing stricter validation of TTL values and implementing more robust cache management policies that prevent maliciously inflated TTL values from being accepted as legitimate cache entries.