CVE-2018-19622 in Wireshark
Summary
by MITRE
In Wireshark 2.6.0 to 2.6.4 and 2.4.0 to 2.4.10, the MMSE dissector could go into an infinite loop. This was addressed in epan/dissectors/packet-mmse.c by preventing length overflows.
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Analysis
by VulDB Data Team • 06/12/2023
The vulnerability identified as CVE-2018-19622 represents a critical denial of service flaw within Wireshark's MMSE dissector component. This issue affects Wireshark versions ranging from 2.6.0 through 2.6.4 and 2.4.0 through 2.4.10, creating a significant operational risk for network analysts and security professionals who rely on this packet analysis tool. The MMSE dissector is responsible for parsing and interpreting Multimedia Messaging Service Element protocol data, which is commonly used in mobile communications and multimedia messaging applications. The flaw manifests as an infinite loop condition that can cause the entire Wireshark application to become unresponsive, effectively rendering the network analysis capabilities unavailable.
The technical root cause of this vulnerability lies in improper handling of packet length parameters within the dissector logic. Specifically, the implementation in epan/dissectors/packet-mmse.c fails to validate or constrain length values during packet processing, allowing malformed or maliciously crafted MMSE packets to trigger an infinite loop in the dissection routine. This type of vulnerability falls under CWE-129, which addresses improper validation of length parameters, and represents a classic example of a buffer over-read or length overflow condition. When the dissector encounters a packet with an invalid length field, the processing loop continues indefinitely without proper termination conditions, consuming system resources and potentially causing complete application hang.
The operational impact of this vulnerability extends beyond simple application instability, as it can be exploited by adversaries to perform denial of service attacks against systems running affected Wireshark versions. Network security professionals who depend on Wireshark for real-time packet analysis and troubleshooting may find their monitoring capabilities completely compromised when encountering malicious traffic. This vulnerability particularly affects environments where automated network monitoring systems rely on Wireshark for continuous analysis, as a single malicious packet could bring down the entire monitoring infrastructure. The issue aligns with ATT&CK technique T1499.001, which covers network denial of service attacks, and demonstrates how protocol parsing flaws can be leveraged to create system instability.
The remediation implemented in the patched versions addresses the core issue by introducing proper length validation mechanisms within the MMSE dissector. The fix in epan/dissectors/packet-mmse.c specifically prevents length overflows by implementing boundary checks and ensuring that packet length parameters remain within acceptable ranges before processing begins. This approach follows established security practices for protocol parsing and aligns with the principle of least privilege in software design, where all input parameters are validated before use. Organizations should prioritize updating to Wireshark versions that contain this fix to eliminate the risk of exploitation, as the infinite loop condition can be triggered by any MMSE packet that meets the specific malformed criteria. The vulnerability serves as a reminder of the critical importance of proper input validation in network protocol parsers, as these components are frequently targeted by attackers seeking to disrupt network monitoring and analysis operations.