CVE-2017-7748 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the WSP dissector could go into an infinite loop, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-wsp.c by adding a length check.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7748 represents a critical denial of service flaw within Wireshark's WSP dissector component. This issue affected versions ranging from 2.2.0 through 2.2.5 and 2.0.0 through 2.0.11, exposing users to potential system instability through crafted network traffic or malformed capture files. The WSP dissector is responsible for analyzing Wireless Specific Protocol packets, which are commonly encountered in wireless network analysis scenarios. The flaw manifested as an infinite loop condition that could completely consume system resources and render the network analysis tool unusable. This vulnerability directly impacts the reliability and availability of network forensic analysis operations, particularly in environments where Wireshark serves as a primary diagnostic tool for network troubleshooting and security monitoring.
The technical root cause of this vulnerability stems from inadequate input validation within the packet processing logic of the WSP dissector module. Specifically, the implementation in epan/dissectors/packet-wsp.c failed to perform proper length validation checks on incoming packet data structures. When processing malformed packets containing crafted length fields or irregular data sequences, the dissector would enter a recursive processing loop where it continuously re-evaluated the same packet data without proper termination conditions. This behavior aligns with CWE-835, which describes infinite loops or iterations without proper exit conditions, making it particularly dangerous in network analysis tools where continuous packet processing is expected. The vulnerability exploited the fundamental assumption that packet data would conform to expected protocols, failing to account for maliciously crafted inputs that could manipulate the parsing logic into an endless cycle.
The operational impact of CVE-2017-7748 extends beyond simple service disruption to potentially compromise entire network monitoring infrastructures. Network security analysts and forensic investigators relying on Wireshark for real-time packet analysis could experience complete tool failure when encountering maliciously crafted traffic or corrupted capture files. This vulnerability particularly affects environments where automated monitoring systems continuously process network data streams, as the infinite loop would cause sustained resource exhaustion and system instability. The flaw could be exploited through packet injection attacks, where adversaries craft specially formatted WSP packets designed to trigger the loop condition, or by providing maliciously constructed capture files that contain corrupted WSP data structures. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1499.001, which involves network disruption through resource exhaustion, and represents a significant threat to network security operations centers that depend on stable packet analysis tools for incident response and threat hunting activities.
The remediation implemented in the affected Wireshark versions addressed the vulnerability through the addition of proper length validation checks within the packet-wsp.c file. This defensive programming approach ensures that packet data structures are validated against expected size parameters before processing continues, preventing the infinite loop condition from occurring. The fix demonstrates the importance of input validation and boundary checking in network protocol parsers, where malformed data could otherwise lead to unpredictable system behavior. Security practitioners should prioritize updating to patched versions of Wireshark to eliminate this vulnerability, as the remediation directly addresses the core flaw without introducing significant performance overhead or breaking existing functionality. Organizations maintaining network monitoring capabilities should also consider implementing additional input validation measures at network boundaries to further reduce the risk of exploitation through malformed packet traffic.