CVE-2016-2523 in Wireshark
Summary
by MITRE
The dnp3_al_process_object function in epan/dissectors/packet-dnp.c in the DNP3 dissector in Wireshark 1.12.x before 1.12.10 and 2.0.x before 2.0.2 allows remote attackers to cause a denial of service (infinite loop) via a crafted packet.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-2523 represents a critical denial of service flaw within Wireshark's DNP3 protocol dissector implementation. This issue affects versions of Wireshark prior to 1.12.10 and 2.0.2, specifically targeting the dnp3_al_process_object function located in epan/dissectors/packet-dnp.c. The flaw manifests when processing specially crafted DNP3 packets, creating a condition that leads to an infinite loop in the dissector's processing logic. The DNP3 protocol, or Distributed Network Protocol, is widely used in critical infrastructure applications including electric power systems, water treatment facilities, and other industrial control systems where reliable network monitoring is essential for operational integrity.
The technical root cause of this vulnerability lies in inadequate input validation and loop termination logic within the DNP3 dissector component. When a maliciously crafted packet is processed by the dnp3_al_process_object function, the dissector enters a state where it continuously iterates through a processing loop without proper exit conditions. This infinite loop consumes excessive CPU resources and effectively renders the Wireshark application unresponsive, preventing further packet analysis and network monitoring operations. The vulnerability demonstrates poor defensive programming practices where the dissector fails to implement proper bounds checking or loop limit enforcement when handling malformed DNP3 object data structures. This flaw aligns with CWE-835, which specifically addresses infinite loops in software implementations where loop termination conditions are not properly enforced.
The operational impact of this vulnerability extends beyond simple application instability, particularly in environments where Wireshark serves as a critical network monitoring tool for industrial control systems. Network administrators and security analysts who rely on Wireshark for real-time traffic analysis may experience complete service disruption when encountering malicious DNP3 traffic, potentially masking actual security incidents or network anomalies. The remote nature of the attack means that an unauthenticated attacker can trigger this condition from anywhere on the network, making it particularly dangerous in operational technology environments where network segmentation may be limited. This vulnerability directly affects the availability aspect of the CIA security triad, as it compromises the ability of network monitoring systems to function properly, potentially creating blind spots in security monitoring for critical infrastructure networks.
Organizations should immediately implement mitigation strategies including updating to Wireshark versions 1.12.10 or 2.0.2, which contain the necessary patches to address this infinite loop condition. Network administrators should also consider implementing network segmentation and access controls to limit exposure to potentially malicious traffic, particularly in industrial control system environments where DNP3 protocol traffic is common. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for network denial of service attacks, highlighting the importance of protecting network monitoring infrastructure from such attacks. Additionally, implementing network intrusion detection systems that can identify and block malformed DNP3 traffic patterns may provide additional defense in depth. Regular security assessments and vulnerability management programs should include verification of dissector components within network analysis tools to prevent similar issues from affecting other protocol implementations in similar software environments.