CVE-2021-4183: 
Wireshark vulnerability analysis and mitigation

CVE-2021-4183 is a vulnerability discovered in Wireshark 3.6.0's pcapng file parser that was disclosed on December 29, 2021. The vulnerability affects the pcapng file parser component and allows denial of service via a crafted capture file (Wireshark Advisory).

The vulnerability manifests as a heap-buffer-overflow in the pcapng_process_options function when processing pcapng files. When analyzing the crash with AddressSanitizer, it was found that the issue occurs during a READ operation of size 2 at a memory location that is 32 bytes beyond an allocated 128-byte region (Wireshark Issue).

The vulnerability allows attackers to cause a denial of service condition by convincing a user to open a specially crafted packet capture file. This can result in Wireshark crashing during file analysis (Wireshark Advisory).

The vulnerability can be triggered by processing a malformed pcapng capture file. A proof of concept exists demonstrating the crash can be reproduced using the command 'tshark -nVxr' with a specially crafted file (Wireshark Issue).

The vulnerability was fixed in Wireshark version 3.6.1. Users are advised to upgrade to this version or later to mitigate the issue. No workarounds were provided for earlier versions (Wireshark Advisory, Fedora Update).