CVE-2007-3409 in Net Dns
Summary
by MITRE
Net::DNS before 0.60, a Perl module, allows remote attackers to cause a denial of service (stack consumption) via a malformed compressed DNS packet with self-referencing pointers, which triggers an infinite loop.
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Analysis
by VulDB Data Team • 01/17/2025
The vulnerability identified as CVE-2007-3409 affects the Net::DNS Perl module version 0.60 and earlier, presenting a significant denial of service risk that stems from improper handling of DNS packet structures. This flaw specifically targets the module's ability to process compressed DNS records, where the parser fails to properly validate pointer references within DNS messages. When a maliciously crafted DNS packet contains self-referencing pointers that create circular references, the module's parsing logic becomes trapped in an infinite loop, consuming excessive stack resources and ultimately leading to system resource exhaustion.
The technical implementation of this vulnerability resides in the DNS decompression algorithm within the Net::DNS module, which lacks proper loop detection mechanisms when processing compressed record pointers. According to CWE-400, this represents a classic case of uncontrolled resource consumption where the application fails to implement adequate bounds checking or cycle detection in its parsing routines. The flaw manifests when the parser encounters a pointer that references itself or creates a circular chain of references, causing the recursive decompression process to continue indefinitely without proper termination conditions.
From an operational perspective, this vulnerability presents a severe risk to systems that rely on Net::DNS for DNS resolution and packet processing tasks. Attackers can exploit this weakness by crafting specially formatted DNS responses or queries containing malformed compressed pointers, which when processed by vulnerable systems trigger the infinite loop condition. The impact extends beyond simple service disruption as the stack consumption can lead to complete system hangs, application crashes, or resource exhaustion that affects other critical services running on the same infrastructure. This makes the vulnerability particularly dangerous in network infrastructure devices, DNS servers, and applications that handle untrusted DNS traffic.
The attack vector for this vulnerability is particularly insidious as it requires minimal privileges and can be executed through standard DNS traffic. According to ATT&CK framework tactic T1499, this represents a resource exhaustion technique that can be used to perform denial of service attacks against targeted systems. The vulnerability is most prevalent in environments where DNS resolution is frequently performed and where systems process untrusted DNS data without proper sanitization. Mitigation strategies should focus on immediate module updates to version 0.60 or later, where the parsing logic has been enhanced to detect and terminate circular pointer references. Additionally, network-level protections such as DNS traffic filtering, rate limiting, and implementing proper input validation at the application layer can provide defense-in-depth measures against exploitation attempts.
The broader implications of this vulnerability highlight the critical importance of proper input validation and bounds checking in network protocol implementations. This flaw demonstrates how seemingly benign parsing operations can become attack vectors when adequate safeguards are not implemented, emphasizing the need for robust security practices in network utility libraries. Organizations should conduct comprehensive vulnerability assessments to identify all systems using affected versions of Net::DNS and implement patch management procedures to ensure timely remediation of such critical security flaws. The vulnerability also underscores the necessity of thorough testing of parsing routines against malformed inputs, particularly in security-sensitive applications that process network protocols.