CVE-2022-3725: Wireshark OPUS Dissector DOS Vulnerability

CVE-2022-3725 Overview

CVE-2022-3725 is an out-of-bounds write vulnerability (CWE-787) affecting the OPUS protocol dissector in Wireshark versions 3.6.0 through 3.6.8. This vulnerability allows attackers to cause a denial of service condition through packet injection or by convincing a user to open a specially crafted capture file. The OPUS dissector fails to properly validate input boundaries, leading to memory corruption that crashes the application.

Critical Impact

Successful exploitation results in a complete denial of service, crashing Wireshark and disrupting network analysis activities. This can be leveraged by attackers to prevent security analysts from examining malicious network traffic.

Affected Products

• Wireshark versions 3.6.0 through 3.6.8
• Fedora 37 (ships vulnerable Wireshark packages)

Discovery Timeline

• 2022-10-27 - CVE-2022-3725 published to NVD
• 2025-05-09 - Last updated in NVD database

Technical Details for CVE-2022-3725

Vulnerability Analysis

The vulnerability resides in the OPUS protocol dissector component of Wireshark. OPUS is an audio codec commonly used in VoIP applications and WebRTC communications. When Wireshark parses network packets containing OPUS protocol data, the dissector processes the packet contents to display human-readable information about the audio stream.

The flaw is classified as CWE-787 (Out-of-Bounds Write), indicating that the OPUS dissector writes data beyond the boundaries of allocated memory buffers. This type of memory corruption typically occurs when input length validation is missing or improperly implemented, allowing malformed packets to trigger writes to unintended memory locations.

The vulnerability can be exploited remotely over the network without requiring authentication or user interaction beyond having Wireshark actively capturing traffic. An attacker positioned on the same network segment, or capable of injecting packets, can send specially crafted OPUS protocol packets that trigger the vulnerable code path.

Root Cause

The root cause is an out-of-bounds write condition in the OPUS protocol dissector. The dissector fails to properly validate the boundaries of packet data before writing to memory buffers. When processing malformed OPUS packets with unexpected field lengths or structures, the dissector writes beyond allocated buffer boundaries, corrupting adjacent memory and causing the application to crash.

Attack Vector

The attack vector is network-based and can be executed in two primary ways:

1. Packet Injection: An attacker on the same network segment can inject malicious packets containing crafted OPUS protocol data. When Wireshark captures and attempts to dissect these packets, the vulnerable code path is triggered.

2. Crafted Capture File: An attacker can create a malicious PCAP or PCAPNG capture file containing the exploit payload and distribute it to targets. When a victim opens the file in Wireshark for analysis, the crash occurs.

The vulnerability is particularly concerning in incident response scenarios where analysts may be examining potentially malicious traffic captures, as the malicious content could be embedded within files obtained from compromised systems.

Detection Methods for CVE-2022-3725

Indicators of Compromise

• Unexpected Wireshark application crashes during packet capture or file analysis
• Crash dumps referencing the OPUS dissector or packet-opus.c components
• Presence of suspicious PCAP/PCAPNG files with malformed OPUS protocol data
• Network traffic containing unusual OPUS protocol packets with malformed headers

Detection Strategies

• Monitor for repeated Wireshark process crashes across analyst workstations
• Implement file integrity monitoring on network capture file repositories
• Deploy network intrusion detection rules to identify malformed OPUS protocol packets
• Review system logs for Wireshark crash events correlating with specific capture files

Monitoring Recommendations

• Configure crash reporting to aggregate Wireshark failures for pattern analysis
• Establish baseline metrics for Wireshark stability to detect anomalous crash rates
• Monitor network analysis workstations for unusual process terminations
• Track file access patterns for PCAP files that may be associated with crashes

How to Mitigate CVE-2022-3725

Immediate Actions Required

• Upgrade Wireshark to version 3.6.9 or later immediately on all systems
• Disable the OPUS protocol dissector if upgrade is not immediately possible using the Analyze → Enabled Protocols menu
• Exercise caution when opening capture files from untrusted sources
• Consider using isolated virtual machines for analyzing potentially malicious capture files

Patch Information

Wireshark has released version 3.6.9 which addresses this vulnerability. The fix implements proper boundary checking in the OPUS protocol dissector to prevent out-of-bounds write conditions. Detailed information is available in the Wireshark Security Advisory and the Wireshark Issue Report.

Fedora users should update via their package manager, as documented in the Fedora Package Announcement. Gentoo users can reference the Gentoo GLSA 2023-02 for guidance.

Workarounds

• Disable the OPUS dissector in Wireshark via Analyze → Enabled Protocols → search for "OPUS" → uncheck
• Use command-line filtering with tshark to exclude OPUS traffic: -Y "not opus"
• Process untrusted capture files on isolated systems without network connectivity
• Consider using alternative packet analysis tools for examining untrusted captures until patching is complete

# Disable OPUS dissector via command line
tshark -o "opus.enabled:FALSE" -r suspicious_capture.pcap

# Filter out OPUS packets during capture
tshark -Y "not opus" -i eth0 -w filtered_capture.pcap