CVE-2017-7745 in Wireshark
Summary
by MITRE
In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the SIGCOMP dissector could go into an infinite loop, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-sigcomp.c by correcting a memory-size check.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7745 represents a critical denial of service flaw within Wireshark's SIGCOMP dissector component. This issue affects versions 2.2.0 through 2.2.5 and 2.0.0 through 2.0.11, where the dissector fails to properly handle malformed input data during packet analysis. The SIGCOMP dissector is responsible for decompressing SIGCOMP compressed packets, which are commonly used in VoIP applications to reduce bandwidth consumption. When encountering specially crafted malformed packets or capture files, the dissector enters an infinite loop, causing the application to consume excessive CPU resources and eventually become unresponsive.
The technical root cause of this vulnerability stems from an inadequate memory-size check within the packet-sigcomp.c file in Wireshark's epan/dissectors directory. The flaw occurs when the dissector processes compressed data without proper validation of buffer boundaries or memory allocation limits. This allows an attacker to craft packets that trigger the infinite loop condition through either direct packet injection into a network capture or by providing a maliciously formatted capture file. The memory-size check failure creates a scenario where the dissector's decompression algorithm continues processing without proper termination conditions, leading to resource exhaustion and application instability.
The operational impact of this vulnerability extends beyond simple denial of service, as it can affect network analysis operations critical to security monitoring and incident response. Network security professionals relying on Wireshark for packet analysis and troubleshooting may find their analysis tools become unresponsive when processing malicious traffic or corrupted capture files. This vulnerability particularly affects environments where automated network monitoring systems depend on Wireshark for real-time packet inspection, as the infinite loop can cause complete system unresponsiveness. The issue also poses risks in forensic analysis scenarios where analysts might inadvertently process compromised capture files, leading to extended downtime and potential loss of critical network traffic data.
Mitigation strategies for CVE-2017-7745 involve immediate upgrading to Wireshark versions 2.2.6 or 2.0.12, which contain the necessary patch addressing the memory-size check flaw. Organizations should also implement network segmentation and traffic filtering to prevent potentially malicious packets from reaching systems running vulnerable Wireshark versions. Security teams should consider implementing automated monitoring for unusual CPU usage patterns that might indicate the infinite loop condition. Additionally, capture file validation procedures should be enhanced to include pre-processing checks for malformed SIGCOMP data before analysis. This vulnerability aligns with CWE-129, which addresses improper validation of array index values, and relates to ATT&CK technique T1499.001 for network denial of service attacks, emphasizing the importance of robust input validation in network security tools.