CVE-2005-1278 in tcpdump
Summary
by MITRE
The isis_print function, as called by isoclns_print, in tcpdump 3.9.1 and earlier allows remote attackers to cause a denial of service (infinite loop) via a zero length, as demonstrated using a GRE packet.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/24/2024
The vulnerability identified as CVE-2005-1278 represents a critical denial of service flaw within tcpdump version 3.9.1 and earlier releases. This issue manifests through the isis_print function which is invoked by the isoclns_print function when processing network packets. The specific weakness occurs when tcpdump encounters a GRE packet containing a zero-length field, creating a condition that triggers an infinite loop in the packet parsing routine. This flaw demonstrates the classic pattern of insufficient input validation where the software fails to properly handle edge cases in packet structure, particularly when dealing with variable-length fields that may legitimately contain zero values.
The technical implementation of this vulnerability stems from how tcpdump processes IS-IS (Intermediate System to Intermediate System) protocol packets within the context of GRE (Generic Routing Encapsulation) tunneling. When the isoclns_print function processes a packet with a zero-length field, it enters an infinite loop because the parsing logic does not account for the possibility of zero-length data segments. This condition violates the expected behavior of packet parsing routines which should gracefully handle all valid packet structures, including those with empty fields. The vulnerability is categorized under CWE-835, which specifically addresses infinite loops in software, and represents a failure to implement proper loop termination conditions when processing variable-length data structures. The flaw operates at the network protocol parsing layer where tcpdump attempts to decode and display packet contents, making it particularly dangerous as it can be triggered by remote network traffic without requiring authentication or special privileges.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by remote attackers to consume system resources indefinitely. When an affected tcpdump instance processes a maliciously crafted GRE packet, the infinite loop causes the application to remain in a busy-wait state, consuming CPU cycles and potentially leading to system resource exhaustion. This denial of service scenario is particularly concerning in network monitoring environments where tcpdump is commonly deployed to capture and analyze network traffic, as it can render network monitoring tools completely ineffective. The vulnerability affects network administrators who rely on tcpdump for troubleshooting and security analysis, as any attempt to capture traffic containing the malicious packet structure will result in the tool becoming unresponsive. From an attacker perspective, this represents a low-effort, high-impact method for disrupting network monitoring operations, potentially allowing for evasion of network security measures that depend on continuous packet analysis.
Mitigation strategies for CVE-2005-1278 focus on both immediate remediation and long-term defensive measures. The most direct solution involves upgrading tcpdump to version 3.9.2 or later, where the infinite loop condition has been addressed through proper input validation and loop termination logic. Network administrators should also implement packet filtering rules at network boundaries to prevent the transmission of malformed GRE packets that could trigger this condition. Additionally, monitoring systems should be configured to detect abnormal cpu usage patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and proper error handling in network protocol parsers, aligning with ATT&CK technique T1499.001 which covers network denial of service attacks. Organizations should also consider implementing redundant monitoring solutions and ensuring proper patch management processes are in place to prevent similar vulnerabilities from affecting other network analysis tools. Security teams should conduct regular vulnerability assessments of network monitoring infrastructure to identify and remediate similar edge case handling issues in other protocol parsers and network analysis tools.