CVE-2017-7746 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the SLSK dissector could go into an infinite loop, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-slsk.c by adding checks for the remaining length.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7746 represents a critical denial of service flaw within Wireshark's SLSK dissector functionality. This issue affects specific versions of Wireshark including releases 2.2.0 through 2.2.5 and 2.0.0 through 2.0.11, where the software's ability to process network traffic becomes severely compromised. The SLSK protocol dissector is designed to analyze and decode Soulseek protocol traffic, which is commonly used in peer-to-peer file sharing networks. When confronted with malformed packet data or specially crafted capture files, the dissector enters an infinite loop state that consumes excessive system resources and renders the application unresponsive.
The technical root cause of this vulnerability lies in insufficient input validation within the packet-slsk.c file, specifically within the epan/dissectors directory of Wireshark's source code. The dissector fails to properly check the remaining length of data packets during processing, allowing maliciously crafted packets to trigger a condition where the parsing loop continues indefinitely without proper termination conditions. This flaw operates at the protocol analysis layer, where Wireshark's dissectors attempt to interpret network traffic into human-readable formats, making it particularly dangerous as it can be exploited through both network packet injection and malformed capture file manipulation.
The operational impact of this vulnerability extends beyond simple application instability, as it creates a reliable denial of service condition that can be exploited by attackers to disrupt network analysis operations. Network security professionals and analysts who rely on Wireshark for traffic inspection and forensic analysis face significant operational risks when encountering malicious traffic or corrupted capture files. The infinite loop behavior can cause system resource exhaustion, potentially leading to complete system crashes or unresponsiveness, particularly in environments where Wireshark is deployed continuously for network monitoring purposes. This vulnerability directly impacts the availability of network analysis tools that are critical for security operations and incident response activities.
Mitigation strategies for CVE-2017-7746 involve immediate upgrades to Wireshark versions that contain the patched dissector implementation. The fix implemented in packet-slsk.c addresses the core issue by introducing proper length validation checks that prevent the infinite loop condition from occurring. Network administrators should prioritize updating their Wireshark installations to versions 2.2.6 or 2.0.12 and later, which contain the necessary defensive measures. Additionally, implementing network segmentation and traffic filtering can help reduce exposure by limiting access to potentially malicious SLSK protocol traffic. Organizations should also consider implementing capture file validation procedures and establishing network monitoring to detect anomalous behavior patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-835, which addresses infinite loops in software implementations, and represents a classic example of how protocol parsing flaws can lead to denial of service conditions that compromise system availability. The remediation approach follows established security practices outlined in the ATT&CK framework for defensive measures against protocol-based attacks and ensures that network analysis tools maintain their reliability and operational integrity.