CVE-2018-9265 in Wireshark
Summary
by MITRE
In Wireshark 2.4.0 to 2.4.5 and 2.2.0 to 2.2.13, epan/dissectors/packet-tn3270.c has a memory leak.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/26/2023
The vulnerability identified as CVE-2018-9265 represents a memory leak flaw discovered in Wireshark versions ranging from 2.4.0 through 2.4.5 and 2.2.0 through 2.2.13. This issue resides within the TN3270 protocol dissector component located at epan/dissectors/packet-tn3270.c, which is responsible for analyzing and interpreting data from IBM 3270 terminal emulation network traffic. The TN3270 protocol is commonly used in mainframe environments for communication between terminal emulators and host systems, making this vulnerability particularly significant in enterprise network monitoring scenarios where such traffic is frequently analyzed.
The technical flaw manifests as improper memory management within the dissector code that processes TN3270 packets. When Wireshark processes certain malformed or specially crafted TN3270 frames, the application fails to properly release allocated memory resources, resulting in a gradual accumulation of memory consumption over time. This memory leak occurs during the packet dissection process when the dissector handles specific field structures or data sequences within the TN3270 protocol. The vulnerability is classified under CWE-401 as a weakness related to improper management of memory resources, specifically manifesting as a failure to deallocate memory that has been dynamically allocated during packet processing. The flaw does not directly enable arbitrary code execution or privilege escalation, but rather creates a resource exhaustion condition that can impact system stability.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can lead to significant performance degradation in network monitoring environments where Wireshark is deployed continuously. Network administrators and security analysts who rely on Wireshark for extended packet capture sessions may experience system instability, application crashes, or complete service unavailability due to the accumulating memory consumption. In high-volume network environments where TN3270 traffic is common, such as financial institutions, government agencies, or large enterprise networks, this memory leak can cause the monitoring system to become unresponsive or require frequent restarts. The vulnerability aligns with ATT&CK technique T1490 which involves resource exhaustion attacks, where adversaries may exploit such memory leaks to disrupt services or create conditions that enable further exploitation. The issue particularly affects long-running network analysis sessions where continuous packet processing occurs without system intervention.
Mitigation strategies for CVE-2018-9265 primarily involve upgrading to patched versions of Wireshark where the memory leak has been resolved through proper memory management practices. Users should immediately update to Wireshark 2.4.6 or 2.2.14, which contain the necessary code modifications to ensure proper memory deallocation during TN3270 packet processing. Network security teams should implement monitoring procedures to detect unusual memory consumption patterns in Wireshark processes and establish regular maintenance schedules for system restarts to prevent accumulation of leaked memory. Additionally, administrators can implement temporary workarounds such as limiting packet capture duration or using alternative network analysis tools for extended monitoring sessions. The fix demonstrates proper defensive programming practices that align with secure coding standards, ensuring that all dynamically allocated memory is properly freed regardless of processing outcomes. Organizations should also consider implementing automated patch management systems to prevent similar vulnerabilities from remaining unaddressed in their network monitoring infrastructure, as memory leaks can serve as precursors to more serious security issues in long-running applications.