CVE-2018-19624 in Wireshark
Summary
by MITRE
In Wireshark 2.6.0 to 2.6.4 and 2.4.0 to 2.4.10, the PVFS dissector could crash. This was addressed in epan/dissectors/packet-pvfs2.c by preventing a NULL pointer dereference.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/12/2023
The vulnerability identified as CVE-2018-19624 represents a critical NULL pointer dereference flaw within the Wireshark network protocol analyzer software. This issue specifically affects versions ranging from 2.6.0 through 2.6.4 and 2.4.0 through 2.4.10, creating a potential denial of service condition that could be exploited by malicious actors. The flaw resides within the PVFS dissector component which is responsible for analyzing and interpreting Protocol Virtual File System version 2 network traffic. This dissector plays a crucial role in Wireshark's ability to decode and display network packets from systems utilizing PVFS protocols, making it an essential component for network forensic analysis and troubleshooting.
The technical implementation of this vulnerability stems from improper input validation within the packet-pvfs2.c file located in the epan/dissectors directory of Wireshark's source code. When processing specially crafted network packets that conform to the PVFS protocol, the dissector fails to properly check for NULL pointer conditions before attempting to dereference memory addresses. This programming error creates a scenario where the software attempts to access memory locations that have not been properly allocated or initialized, leading to a segmentation fault and subsequent application crash. The flaw directly maps to CWE-476 which defines NULL Pointer Dereference as a condition where a null pointer is dereferenced, and the vulnerability can be categorized under the broader ATT&CK technique T1499.3 for network denial of service attacks targeting application stability.
The operational impact of this vulnerability extends beyond simple application instability, as it creates potential security risks for network administrators and security analysts who rely on Wireshark for critical network monitoring and forensic activities. When exploited, the crash can disrupt ongoing network analysis sessions, potentially causing loss of valuable network traffic data and forcing analysts to restart their monitoring operations. The vulnerability is particularly concerning in environments where Wireshark is used for continuous network monitoring or during security incident investigations, as an attacker could potentially disrupt critical network analysis operations through carefully crafted malicious packets. Additionally, the crash could be leveraged in combination with other attack vectors to create more sophisticated exploitation scenarios, though the primary impact remains focused on service disruption rather than arbitrary code execution.
Mitigation strategies for CVE-2018-19624 involve immediate upgrading to Wireshark versions that have addressed this specific flaw, with the fix implemented in the packet-pvfs2.c file through proper NULL pointer validation. Network administrators should prioritize patching systems running affected Wireshark versions, particularly in environments where the software is used for critical network monitoring or forensic analysis. The implementation of network segmentation and access controls can provide additional defense-in-depth measures, limiting the potential impact of exploitation attempts. Organizations should also consider implementing network intrusion detection systems that can identify and alert on suspicious PVFS protocol traffic patterns, though the most effective mitigation remains the application of the vendor-supplied security patches. Regular security assessments and vulnerability scanning should include verification of Wireshark versions to ensure all systems remain protected against this and similar class of vulnerabilities.