CVE-2018-19623 in Wireshark
Summary
by MITRE
In Wireshark 2.6.0 to 2.6.4 and 2.4.0 to 2.4.10, the LBMPDM dissector could crash. In addition, a remote attacker could write arbitrary data to any memory locations before the packet-scoped memory. This was addressed in epan/dissectors/packet-lbmpdm.c by disallowing certain negative values.
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Analysis
by VulDB Data Team • 06/12/2023
The vulnerability identified as CVE-2018-19623 represents a critical memory corruption issue within Wireshark's LBMPDM dissector component that affected versions ranging from 2.6.0 through 2.6.4 and 2.4.0 through 2.4.10. This flaw resides in the packet dissection engine where the LBMPDM protocol handler fails to properly validate input data, creating a pathway for both denial of service and potential remote code execution scenarios. The vulnerability stems from insufficient bounds checking and input validation mechanisms within the dissector implementation, specifically in the epan/dissectors/packet-lbmpdm.c file where the protocol parsing logic processes incoming packet data without adequate safeguards against malformed or malicious inputs.
The technical exploitation of this vulnerability manifests through a combination of buffer overflow conditions and memory corruption patterns that allow attackers to manipulate memory locations in ways that were never intended by the application's design. When processing specially crafted LBMPDM packets, the dissector could be induced to write arbitrary data to memory locations that precede the packet-scoped memory allocation, effectively creating a memory corruption condition that could lead to application crashes or more severe consequences. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though it specifically demonstrates characteristics of heap-based memory corruption due to the nature of the memory manipulation occurring before packet-scoped allocations. The ATT&CK framework would classify this as a memory corruption technique under the T1055 category of exploitation for privilege escalation, as the vulnerability could potentially be leveraged to execute arbitrary code with the privileges of the Wireshark process.
The operational impact of this vulnerability extends beyond simple application instability to encompass potential security breaches in network monitoring environments where Wireshark serves as a critical tool for network analysis and troubleshooting. Organizations relying on Wireshark for network traffic analysis, forensic investigations, or security monitoring could face significant operational disruptions if attackers exploit this vulnerability, particularly in environments where network traffic is not properly filtered or where Wireshark is deployed in active monitoring modes. The remote exploitation capability means that attackers need only send maliciously crafted LBMPDM packets to the target system to trigger the vulnerability, making it particularly dangerous in network environments where untrusted traffic flows through monitoring systems. The crash conditions could also be used as a vector for denial of service attacks against network monitoring infrastructure, potentially disrupting critical network analysis capabilities that organizations depend upon for maintaining security posture and operational continuity.
The remediation implemented in the patched versions addresses the core issue by modifying the packet-lbmpdm.c file to disallow certain negative values that were previously accepted by the dissector. This fix represents a defensive programming approach that prevents the dissector from processing inputs that could lead to memory corruption by establishing proper bounds checking and input validation. The solution aligns with industry best practices for secure coding and follows the principle of least privilege by ensuring that the dissector only processes valid data ranges. Organizations should prioritize immediate deployment of patched versions to protect against this vulnerability, as the window for exploitation remains open for systems running vulnerable versions of Wireshark. The fix demonstrates the importance of proper input validation in protocol dissector implementations and serves as a reminder to security practitioners about the critical need for robust validation mechanisms in network analysis tools that process untrusted data from network traffic.