CVE-2011-2698 in Wireshark
Summary
by MITRE
Off-by-one error in the elem_cell_id_aux function in epan/dissectors/packet-ansi_a.c in the ANSI MAP dissector in Wireshark 1.4.x before 1.4.8 and 1.6.x before 1.6.1 allows remote attackers to cause a denial of service (infinite loop) via an invalid packet.
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Analysis
by VulDB Data Team • 11/18/2021
The vulnerability described in CVE-2011-2698 represents a critical off-by-one error within the ANSI MAP dissector component of Wireshark, specifically affecting versions 1.4.x prior to 1.4.8 and 1.6.x prior to 1.6.1. This flaw exists in the elem_cell_id_aux function located in the epan/dissectors/packet-ansi_a.c file, which is responsible for parsing and dissecting ANSI MAP protocol packets during network traffic analysis. The issue manifests when processing malformed or invalid packets that contain incorrect cell identifier data, creating a condition where the dissector fails to properly handle boundary conditions in its loop structures.
The technical implementation of this vulnerability stems from improper bounds checking within the packet parsing logic, where the function fails to correctly validate array indices or loop counters during the processing of cell identifier elements. When an attacker crafts a specially malformed packet containing invalid cell ID data, the function enters an infinite loop scenario where loop termination conditions are never met due to the off-by-one error. This condition causes the Wireshark application to become unresponsive and consume excessive CPU resources, effectively creating a denial of service condition that impacts the entire network analysis capability of the affected system.
The operational impact of this vulnerability extends beyond simple service disruption, as it directly affects the reliability and availability of network traffic analysis operations that depend on Wireshark for protocol inspection. Network security analysts and administrators who rely on Wireshark for monitoring and troubleshooting network issues face significant operational risks when this vulnerability is exploited, as the infinite loop can bring down the entire analysis environment and prevent critical network monitoring activities. The vulnerability is particularly dangerous in environments where automated network monitoring systems depend on Wireshark for real-time packet analysis and threat detection.
This vulnerability maps to CWE-129, which specifically addresses improper validation of array index values, and aligns with ATT&CK technique T1499.004 for network denial of service attacks. The flaw demonstrates how seemingly minor coding errors in protocol dissectors can create significant security implications, particularly in network analysis tools that process untrusted data from network traffic. The vulnerability's remote exploitability means that attackers can trigger the denial of service condition without requiring local access to the target system, making it a particularly attractive vector for network-based attacks. Organizations should prioritize updating their Wireshark installations to versions 1.4.8 or 1.6.1 and later to address this vulnerability, while also implementing network segmentation and monitoring to detect potential exploitation attempts. The incident highlights the critical importance of thorough input validation and boundary checking in network protocol analysis tools, where malformed packet handling can directly translate into system availability compromises that affect network security operations.