CVE-2024-9781 Overview
CVE-2024-9781 is a denial of service vulnerability affecting Wireshark's AppleTalk and RELOAD Framing protocol dissectors. The vulnerability allows attackers to crash Wireshark through packet injection or by enticing users to open specially crafted capture files. This flaw impacts Wireshark version 4.4.0 and versions 4.2.0 through 4.2.7, affecting security analysts and network administrators who rely on Wireshark for packet analysis.
Critical Impact
Successful exploitation results in denial of service, potentially disrupting critical network monitoring and forensic analysis operations.
Affected Products
- Wireshark version 4.4.0
- Wireshark versions 4.2.0 through 4.2.7
Discovery Timeline
- 2024-10-10 - CVE-2024-9781 published to NVD
- 2024-11-25 - Last updated in NVD database
Technical Details for CVE-2024-9781
Vulnerability Analysis
This vulnerability resides in Wireshark's protocol dissector components responsible for parsing AppleTalk and RELOAD Framing protocols. Protocol dissectors in Wireshark decode network traffic and present it in human-readable format. When processing malformed packets or crafted capture files, these specific dissectors fail to properly handle certain input conditions, leading to an application crash.
The vulnerability is classified under CWE-230 (Improper Handling of Missing Values), indicating that the dissector code fails to adequately handle cases where expected data fields are missing or malformed. This improper handling results in an uncontrolled crash condition that terminates the Wireshark process.
Root Cause
The root cause lies in insufficient input validation within the AppleTalk and RELOAD Framing dissector implementations. When these dissectors encounter unexpected or missing values in packet data, the code path leads to improper memory access or state handling that causes the application to crash. The dissector logic does not adequately account for edge cases where protocol fields deviate from expected formats.
Attack Vector
The attack vector is network-based and does not require authentication or user interaction for the packet injection scenario. An attacker can exploit this vulnerability through two primary methods:
Packet Injection: By sending maliciously crafted AppleTalk or RELOAD Framing packets to a network segment being monitored by a vulnerable Wireshark instance, an attacker can trigger the crash condition remotely.
Crafted Capture File: An attacker can create a malicious PCAP file containing crafted packets and distribute it to targets. When an analyst opens this capture file in a vulnerable Wireshark version, the application crashes.
The vulnerability mechanism involves sending or including packets with specific malformed structures that trigger the improper handling condition in the dissector code. For detailed technical information about the specific packet structures involved, refer to GitLab Wireshark Issue #20114.
Detection Methods for CVE-2024-9781
Indicators of Compromise
- Unexpected Wireshark application crashes during network capture or file analysis sessions
- Error logs indicating dissector failures in AppleTalk or RELOAD Framing modules
- Presence of suspicious PCAP files with unusual AppleTalk or RELOAD protocol traffic
- Network traffic containing malformed AppleTalk or RELOAD Framing packets
Detection Strategies
- Monitor for repeated Wireshark process crashes on analyst workstations and network monitoring systems
- Implement network intrusion detection rules to identify anomalous AppleTalk or RELOAD Framing protocol traffic
- Deploy application crash monitoring to detect exploitation attempts in real-time
- Audit received capture files before opening in production Wireshark instances
Monitoring Recommendations
- Enable crash reporting and logging for Wireshark processes across the environment
- Monitor endpoints running Wireshark for unexpected application terminations
- Implement file integrity monitoring for capture file directories to detect potentially malicious PCAP files
- Review network traffic logs for unusual AppleTalk protocol activity, especially in environments where this protocol is not expected
How to Mitigate CVE-2024-9781
Immediate Actions Required
- Upgrade Wireshark to version 4.4.1 or later (for 4.4.x branch) or version 4.2.8 or later (for 4.2.x branch)
- Disable AppleTalk and RELOAD Framing protocol dissectors if they are not required for analysis operations
- Avoid opening capture files from untrusted sources until patching is complete
- Consider using TShark with limited dissectors enabled for processing untrusted capture files
Patch Information
Wireshark has released security patches addressing this vulnerability. Users should update to the latest stable release in their respective version branch. Detailed patch information and download links are available in the Wireshark Security Advisory WNPA-SEC-2024-13.
Workarounds
- Disable the AppleTalk dissector using the Wireshark Analyze > Enabled Protocols menu
- Disable the RELOAD Framing dissector through the same protocol management interface
- Use command-line options to disable specific dissectors when running TShark for batch processing
- Implement network segmentation to limit exposure of monitoring workstations to untrusted traffic
# Disable specific dissectors via command line when using tshark
tshark -o "atalk.heuristic_atalk:FALSE" -r capture.pcap
# List enabled protocols and selectively disable vulnerable dissectors
tshark -G protocols | grep -i "appletalk\|reload"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
