CVE-2003-0108 in Tcpdump
Summary
by MITRE
isakmp_sub_print in tcpdump 3.6 through 3.7.1 allows remote attackers to cause a denial of service (CPU consumption) via a certain malformed ISAKMP packet to UDP port 500, which causes tcpdump to enter an infinite loop.
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Analysis
by VulDB Data Team • 10/12/2024
The vulnerability identified as CVE-2003-0108 represents a critical denial of service flaw within tcpdump versions 3.6 through 3.7.1 that specifically targets the Internet Security Association and Key Management Protocol implementation. This issue occurs when tcpdump processes malformed ISAKMP packets sent to UDP port 500, which serves as the standard port for Internet Key Exchange operations. The flaw manifests in the isakmp_sub_print function, which is responsible for parsing and displaying ISAKMP packet contents during network traffic analysis. When an attacker crafts a specially malformed ISAKMP packet, the function enters an infinite loop that consumes excessive CPU resources, effectively rendering the affected system unable to process legitimate network traffic.
The technical exploitation of this vulnerability relies on the improper handling of ISAKMP packet structures within tcpdump's parsing logic. The isakmp_sub_print function fails to implement adequate bounds checking or loop termination conditions when processing malformed packet data, allowing an attacker to craft packets that trigger recursive or iterative processing patterns that never complete. This behavior aligns with CWE-838, which describes insufficient input validation leading to arbitrary code execution or denial of service conditions. The vulnerability specifically affects the packet parsing engine's ability to handle malformed data structures, creating a scenario where normal network monitoring operations become impossible due to the overwhelming CPU consumption.
From an operational perspective, this vulnerability presents significant risks to network security monitoring infrastructure and can be exploited by attackers to disrupt network operations. Since tcpdump is widely used for network traffic analysis and security monitoring, an attacker could potentially cause widespread service disruption by targeting systems running vulnerable versions. The impact extends beyond simple denial of service as it affects the integrity of network monitoring capabilities, potentially allowing other attacks to go undetected while the system becomes overwhelmed. This vulnerability particularly impacts security operations centers and network monitoring systems that rely on tcpdump for real-time traffic analysis, creating a window of opportunity for attackers to conduct reconnaissance or execute more sophisticated attacks while the monitoring infrastructure is compromised.
The mitigation strategy for CVE-2003-0108 involves immediate upgrading to tcpdump versions 3.7.2 or later, where the problematic isakmp_sub_print function has been patched to properly handle malformed ISAKMP packets. Network administrators should also implement network segmentation and access control measures to limit exposure of tcpdump instances to untrusted networks. Additionally, implementing rate limiting and packet filtering rules at the network boundary can help reduce the impact of such attacks by limiting the volume of traffic that reaches vulnerable systems. This vulnerability demonstrates the importance of input validation and proper error handling in network security tools, as outlined in the ATT&CK framework under the technique of privilege escalation through software exploitation. Organizations should also consider implementing intrusion detection systems that can identify and alert on suspicious ISAKMP traffic patterns that may indicate exploitation attempts. The incident underscores the critical need for maintaining up-to-date security tooling and implementing comprehensive vulnerability management processes to prevent exploitation of known flaws in network monitoring infrastructure.