CVE-2003-1113 in SIP Express Router
Summary
by MITRE
The Session Initiation Protocol (SIP) implementation in IPTel SIP Express Router 0.8.9 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via crafted INVITE messages, as demonstrated by the OUSPG PROTOS c07-sip test suite.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability described in CVE-2003-1113 represents a critical flaw in the Session Initiation Protocol implementation within IPTel SIP Express Router version 0.8.9 and earlier systems. This vulnerability manifests through malformed INVITE messages that can be crafted by remote attackers to exploit the SIP stack, potentially leading to both denial of service conditions and arbitrary code execution. The issue was specifically demonstrated using the OUSPG PROTOS c07-sip test suite, which validated the exploitability of this vulnerability in real-world scenarios. The vulnerability affects the core communication infrastructure of VoIP systems, making it particularly dangerous for organizations relying on SIP-based voice and video communication services.
The technical root cause of this vulnerability lies in inadequate input validation and memory handling within the SIP implementation. When the SIP Express Router receives crafted INVITE messages, the system fails to properly validate the incoming data structures, leading to buffer overflows or other memory corruption issues. This allows attackers to manipulate the application's execution flow and potentially inject malicious code into the running process. The flaw demonstrates poor defensive programming practices where the system does not adequately sanitize or check the integrity of incoming SIP messages before processing them. According to CWE standards, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, and CWE-787, which covers out-of-bounds write operations. The vulnerability also aligns with ATT&CK technique T1190, which involves exploiting vulnerabilities in software to gain unauthorized access or execute arbitrary code.
The operational impact of CVE-2003-1113 extends beyond simple service disruption to potentially compromise the entire VoIP infrastructure. Organizations using affected SIP implementations face significant risks including complete service outages that can disrupt business communications, unauthorized access to voice and video communication channels, and potential data exfiltration through command execution capabilities. The vulnerability is particularly concerning because SIP servers typically run with elevated privileges to manage network communications, making successful exploitation potentially devastating. Attackers could leverage this vulnerability to establish persistent access points within network infrastructure, creating backdoors for future attacks. The demonstrated exploit through the OUSPG PROTOS test suite indicates that this vulnerability is not theoretical but has been validated in practical testing environments, increasing the likelihood of real-world exploitation.
Mitigation strategies for this vulnerability require immediate patching of affected systems to the latest versions of SIP Express Router that address the buffer overflow conditions. Organizations should implement network segmentation and access controls to limit exposure of SIP servers to untrusted networks, using firewalls to restrict SIP traffic to authorized endpoints only. Input validation measures should be strengthened through the implementation of proper message parsing and sanitization routines that check message lengths, headers, and content before processing. Network monitoring systems should be configured to detect unusual SIP traffic patterns that might indicate exploitation attempts, and intrusion detection systems should be updated to recognize signatures associated with this specific vulnerability. Security audits should be conducted to identify all instances of affected software and ensure comprehensive remediation across the entire communication infrastructure. Additionally, organizations should consider implementing SIP-specific security measures such as authentication mechanisms and encryption protocols to add additional layers of protection beyond the basic patching requirements.