CVE-2017-5597 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.3 and 2.0.0 to 2.0.9, the DHCPv6 dissector could go into a large loop, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-dhcpv6.c by changing a data type to avoid an integer overflow.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2017-5597 represents a critical denial of service flaw within Wireshark's DHCPv6 protocol dissector functionality. This issue affects specific versions of the popular network protocol analyzer, namely Wireshark 2.2.0 through 2.2.3 and 2.0.0 through 2.0.9, creating a significant risk for network security professionals and analysts who rely on this tool for packet analysis. The vulnerability manifests when the DHCPv6 dissector encounters specially crafted packets or malformed capture files that trigger an unintended processing behavior. The flaw operates through a mechanism that causes the dissector to enter an extended loop, consuming excessive computational resources and potentially leading to complete system unresponsiveness or crash conditions.
The technical root cause of this vulnerability stems from an integer overflow condition within the packet-dhcpv6.c file in Wireshark's epan/dissectors directory. This specific implementation flaw occurs when processing DHCPv6 protocol data structures, where an insufficient data type handling allows for overflow conditions that result in the dissector entering an infinite loop. The vulnerability is particularly dangerous because it can be triggered through two distinct attack vectors: packet injection directly into network monitoring systems or by providing maliciously crafted capture files that contain malformed DHCPv6 data. The integer overflow specifically affects how the dissector processes certain field values within DHCPv6 packets, causing the loop condition to persist indefinitely until system resources are exhausted or manual intervention occurs.
The operational impact of CVE-2017-5597 extends beyond simple denial of service conditions, as it represents a potential vector for attackers to disrupt network monitoring operations and compromise the availability of critical network analysis infrastructure. Network security teams who depend on Wireshark for real-time packet inspection and troubleshooting could face complete system outages when encountering maliciously crafted DHCPv6 traffic. This vulnerability directly impacts the reliability of network forensic analysis and can be exploited to disrupt network operations in environments where continuous monitoring is essential. The flaw particularly affects organizations that process large volumes of network traffic or those that rely on automated network analysis tools that continuously process capture files, as these systems become vulnerable to resource exhaustion attacks.
The mitigation strategy for this vulnerability involves updating to patched versions of Wireshark where the integer overflow has been addressed through proper data type handling in the packet-dhcpv6.c file. This fix specifically changes the data type used in the dissector to prevent the overflow condition that previously enabled the infinite loop behavior. Security practitioners should also implement network segmentation and monitoring to detect unusual DHCPv6 traffic patterns that might indicate exploitation attempts. Additionally, organizations should consider implementing capture file validation procedures and limiting the processing of untrusted capture files to reduce exposure to this vulnerability. The fix aligns with industry best practices for preventing integer overflow conditions and demonstrates the importance of proper input validation in protocol dissector implementations. This vulnerability classification maps to CWE-191, which specifically addresses integer underflow and overflow conditions, and represents a typical example of how protocol analysis tools can be vulnerable to resource exhaustion attacks through improper data handling. The ATT&CK framework categorizes this as a denial of service technique that can be used to disrupt availability of network monitoring systems, potentially enabling more sophisticated attacks by compromising the integrity of network analysis operations.