CVE-2003-1579 in One Web Server
Summary
by MITRE
Sun ONE (aka iPlanet) Web Server 6 on Windows, when DNS resolution is enabled for client IP addresses, uses a logging format that does not identify whether a dotted quad represents an unresolved IP address, which allows remote attackers to spoof IP addresses via crafted DNS responses containing numerical top-level domains, as demonstrated by a forged 123.123.123.123 domain name, related to an "Inverse Lookup Log Corruption (ILLC)" issue.
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Analysis
by VulDB Data Team • 04/30/2026
The vulnerability described in CVE-2003-1579 represents a significant security flaw in Sun ONE Web Server version 6 running on Windows platforms. This issue stems from the server's handling of DNS resolution and logging mechanisms when client IP addresses are resolved through DNS lookups. The fundamental problem occurs when the web server performs inverse DNS lookups to resolve client IP addresses into hostnames, creating a potential avenue for address spoofing attacks. The vulnerability specifically affects systems where DNS resolution is enabled for client IP addresses, which is a common configuration in enterprise environments where hostname resolution is required for logging or access control purposes.
The technical implementation of this flaw involves the server's logging format which fails to distinguish between resolved IP addresses and unresolved numerical IP addresses that have been spoofed through malicious DNS responses. When the server performs inverse DNS lookups, it processes DNS responses without proper validation of the response legitimacy or origin. This creates a scenario where attackers can manipulate DNS responses to include numerical top-level domains that appear as valid IP addresses in the server logs. The specific demonstration involves forging a DNS response for a domain name like 123.123.123.123, which when resolved by the server appears as a legitimate IP address in the logs, even though it represents a spoofed address that does not actually correspond to any real network host.
The operational impact of this vulnerability extends beyond simple logging corruption and represents a serious threat to network security and audit integrity. Attackers can exploit this flaw to obscure their true IP addresses in server logs, making it extremely difficult for security administrators to track and identify malicious activities. This type of spoofing attack directly impacts the reliability of security monitoring systems and forensic investigations, as the log data becomes contaminated with false information. The vulnerability essentially allows attackers to perform what is known as IP address spoofing or log manipulation, which can be used to evade detection, bypass access controls, or conduct malicious activities while maintaining anonymity in server logs. This issue falls under the broader category of log manipulation and integrity compromise vulnerabilities.
The root cause of this vulnerability aligns with several established security concepts including CWE-20 - Improper Input Validation and CWE-254 - Security Features not Implemented or Configured. The flaw demonstrates poor input validation in the DNS resolution process and inadequate logging mechanisms that fail to properly identify and flag suspicious DNS responses. From an attack perspective, this vulnerability can be categorized under ATT&CK technique T1070.002 - Indicator Removal on Host, as it enables attackers to manipulate log data to hide their activities. The vulnerability also relates to T1566.001 - Phishing via DNS Spoofing, since attackers can leverage DNS manipulation to create false log entries that appear legitimate. Organizations affected by this vulnerability should implement immediate mitigations including disabling DNS resolution for client IP addresses when not required, implementing proper DNS response validation mechanisms, and establishing more robust logging and monitoring procedures that can detect such inconsistencies in log data. The vulnerability highlights the critical importance of proper input validation and the need for security-conscious design in network infrastructure components that handle DNS resolution and logging functions.