CVE-2002-0047 in CIPE
Summary
by MITRE
CIPE VPN package before 1.3.0-3 allows remote attackers to cause a denial of service (crash) via a short malformed packet.
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Analysis
by VulDB Data Team • 04/30/2019
The CIPE VPN package vulnerability identified as CVE-2002-0047 represents a critical denial of service flaw that existed in versions prior to 1.3.0-3. This vulnerability specifically targets the packet processing mechanism within the CIPE implementation, where the software fails to properly validate incoming network packets before attempting to process them. The flaw manifests when remote attackers send malformed packets that contain insufficient data or incorrect packet structures, causing the VPN daemon to crash and terminate its operation. This type of vulnerability falls under the category of improper input validation as classified by CWE-20, where the system does not adequately check the integrity and structure of received data before processing. The vulnerability demonstrates a classic example of insufficient data validation that can be exploited through network-based attacks.
The technical implementation of this vulnerability stems from the lack of proper packet length validation within the CIPE VPN daemon. When the system receives a packet that is shorter than the expected minimum size or contains malformed headers, the processing routine fails to handle these edge cases gracefully. Instead of gracefully rejecting or properly handling such malformed packets, the application attempts to parse the insufficient data, leading to memory access violations or buffer overflows that ultimately result in a complete application crash. This behavior aligns with the ATT&CK technique T1499.004 which describes denial of service attacks targeting network services through malformed packet delivery. The vulnerability affects the availability aspect of the CIA triad by disrupting the normal operation of the VPN service, making it inaccessible to legitimate users.
The operational impact of CVE-2002-0047 extends beyond simple service disruption, as it can be leveraged as part of broader attack campaigns targeting network infrastructure. Organizations relying on CIPE VPN implementations for secure communications face significant risk when exposed to this vulnerability, as attackers can easily exploit it to render VPN services unavailable. The crash condition affects both the client and server components of the VPN infrastructure, potentially leading to complete network access interruption for users who depend on these secure connections. This vulnerability particularly impacts environments where CIPE VPN is used for remote access, site-to-site connections, or as part of larger network security architectures. The exploitability factor is relatively low since it requires network access to the vulnerable service, but the impact can be severe for organizations that depend heavily on continuous VPN availability for business operations.
Mitigation strategies for CVE-2002-0047 should focus on immediate patching of affected CIPE installations to version 1.3.0-3 or later, which contains the necessary input validation fixes. Network administrators should implement additional protective measures such as packet filtering rules that can identify and drop malformed packets before they reach the vulnerable service. The implementation of intrusion detection systems can help identify exploitation attempts by monitoring for unusual packet patterns that match the vulnerability characteristics. Organizations should also consider implementing redundant VPN services or failover mechanisms to maintain availability during potential exploitation events. From a defensive perspective, this vulnerability highlights the importance of robust input validation practices and proper error handling in network service implementations, aligning with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks. Regular security assessments and vulnerability scanning should include checks for outdated VPN implementations to prevent similar issues from affecting network infrastructure.