CVE-2022-0586: Wireshark RTMPT Protocol DoS Vulnerability

CVE-2022-0586 Overview

CVE-2022-0586 is a denial of service vulnerability affecting the RTMPT (Real-Time Messaging Protocol Tunneling) protocol dissector in Wireshark, the widely-used open-source network protocol analyzer. The vulnerability manifests as an infinite loop condition that can be triggered when parsing specially crafted network packets or capture files, causing the application to become unresponsive and consume system resources indefinitely.

This vulnerability impacts network security professionals, system administrators, and forensic analysts who rely on Wireshark for network traffic analysis and troubleshooting. An attacker can exploit this flaw remotely by injecting malicious packets into a network being monitored or by distributing a crafted capture file (pcap/pcapng) that triggers the infinite loop when opened.

Critical Impact

Denial of service via infinite loop in RTMPT protocol dissector allows attackers to render Wireshark instances unresponsive through malicious packet injection or crafted capture files, disrupting network monitoring and forensic analysis operations.

Affected Products

• Wireshark versions 3.6.0 to 3.6.1
• Wireshark versions 3.4.0 to 3.4.11
• Fedora 34 and 35 (via packaged Wireshark)
• Debian Linux 9.0 (via packaged Wireshark)

Discovery Timeline

• February 14, 2022 - CVE-2022-0586 published to NVD
• November 03, 2025 - Last updated in NVD database

Technical Details for CVE-2022-0586

Vulnerability Analysis

The vulnerability resides in the RTMPT protocol dissector component of Wireshark. RTMPT is an encapsulation of RTMP (Real-Time Messaging Protocol) over HTTP, commonly used for streaming media content. The dissector is responsible for parsing and decoding RTMPT traffic to display human-readable information about the protocol exchange.

The flaw is classified as CWE-835 (Loop with Unreachable Exit Condition), indicating that under certain input conditions, the parsing logic enters a loop that cannot terminate normally. This occurs when the dissector processes malformed RTMPT data structures that cause the parsing state machine to cycle indefinitely without advancing through the input buffer or reaching a valid exit condition.

The vulnerability can be exploited over the network without authentication or user interaction beyond simply having Wireshark capture traffic containing the malicious packets. Alternatively, a threat actor could social-engineer a victim into opening a malicious capture file, achieving the same denial of service result.

Root Cause

The root cause is an infinite loop condition (CWE-835) in the RTMPT protocol dissector implementation. The dissector fails to properly validate or advance past certain malformed packet structures, causing the parsing loop to repeat indefinitely. This represents a missing or improper boundary check that should ensure forward progress through the input data during protocol parsing.

The RTMPT dissector processes tunneled RTMP data by parsing HTTP-encapsulated chunks. When encountering specially crafted length fields or chunk boundaries, the code enters a state where loop exit conditions are never satisfied, resulting in the application hanging while consuming CPU resources.

Attack Vector

The attack can be executed through two primary vectors:

1. Network Packet Injection: An attacker on the same network segment or with the ability to inject traffic can send malicious RTMPT packets to a network being monitored by Wireshark. When the vulnerable dissector processes these packets during live capture, the infinite loop is triggered.

2. Crafted Capture File: An attacker can create a malicious pcap or pcapng file containing the exploit payload and distribute it via email, file sharing, or other means. When a victim opens this file in a vulnerable Wireshark version, the denial of service occurs.

The vulnerability requires no authentication or special privileges. The attack complexity is low, making it accessible to unsophisticated attackers. While the impact is limited to availability (denial of service), this can significantly disrupt security operations that depend on network monitoring.

For detailed technical information about this vulnerability, refer to the Wireshark Issue Tracker and the official security advisory.

Detection Methods for CVE-2022-0586

Indicators of Compromise

• Wireshark process consuming excessive CPU resources (approaching 100%) without corresponding network activity
• Wireshark application becoming unresponsive during live packet capture or when opening capture files
• Presence of RTMPT traffic with abnormal or malformed packet structures in network captures
• System logs indicating application hangs or forced terminations of Wireshark processes

Detection Strategies

• Monitor system processes for Wireshark instances exhibiting abnormally high CPU utilization that persists over time
• Implement network intrusion detection rules to identify malformed RTMPT traffic patterns that could indicate exploitation attempts
• Conduct version audits across the environment to identify systems running vulnerable Wireshark versions (3.6.0-3.6.1, 3.4.0-3.4.11)
• Review endpoint telemetry for repeated Wireshark crashes or hangs that may indicate targeted exploitation

Monitoring Recommendations

• Deploy application performance monitoring on systems used for network analysis to detect unusual resource consumption patterns
• Configure alerting for Wireshark process anomalies including excessive runtime, memory growth, or unresponsive states
• Maintain an inventory of Wireshark installations and their versions to facilitate rapid identification of vulnerable deployments
• Consider sandboxing Wireshark operations, especially when analyzing untrusted capture files

How to Mitigate CVE-2022-0586

Immediate Actions Required

• Upgrade Wireshark to version 3.6.2 or later for the 3.6.x branch
• Upgrade Wireshark to version 3.4.12 or later for the 3.4.x branch
• Apply operating system package updates for Fedora, Debian, and other distributions that provide Wireshark packages
• Restrict handling of untrusted capture files until systems are patched

Patch Information

Wireshark has released security updates that address this vulnerability. Users should upgrade to the following minimum versions:

• Wireshark 3.6.x branch: Update to version 3.6.2 or later
• Wireshark 3.4.x branch: Update to version 3.4.12 or later

For Linux distributions, apply the latest package updates:

• Fedora 34/35: Install updates via dnf update wireshark
• Debian 9 (Stretch): Refer to the Debian LTS Announcement for backported security fixes
• Gentoo: Review GLSA 202210-04 for update instructions

Consult the Wireshark Security Advisory for official guidance.

Workarounds

• Disable the RTMPT protocol dissector if RTMPT traffic analysis is not required for your use case
• Avoid opening capture files from untrusted or unknown sources until the patch is applied
• Use network capture tools without the vulnerable dissector (such as tcpdump for capture only) and analyze files on patched systems
• Implement process resource limits to prevent runaway Wireshark processes from consuming all system resources

# Disable RTMPT dissector via command line
wireshark --disable-protocol rtmpt

# Alternative: Use tshark with protocol disabled
tshark --disable-protocol rtmpt -r capture.pcap

# Set process resource limits on Linux (example using ulimit)
ulimit -t 300  # Limit CPU time to 300 seconds before launching Wireshark