CVE-2023-0667: Wireshark Buffer Overflow Vulnerability

CVE-2023-0667 Overview

CVE-2023-0667 is a heap-based buffer overflow vulnerability in Wireshark, the widely-used network protocol analyzer. The vulnerability exists in the MSMMS (Microsoft Media Server) protocol dissector and stems from a failure to properly validate the length field provided in attacker-crafted MSMMS packets. In an unusual configuration, successful exploitation could allow an attacker to cause a denial of service condition or potentially achieve code execution in the context of the process running Wireshark.

Critical Impact

Heap-based buffer overflow in Wireshark's MSMMS dissector could lead to denial of service or potential code execution when processing malicious network captures.

Affected Products

• Wireshark version 4.0.5 and prior
• Wireshark version 4.0.x branch
• Wireshark version 3.6.x branch

Discovery Timeline

• 2023-06-07 - CVE-2023-0667 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2023-0667

Vulnerability Analysis

This vulnerability is classified under CWE-122 (Heap-based Buffer Overflow) and CWE-787 (Out-of-bounds Write). The flaw exists within the MSMMS protocol dissector, which is responsible for parsing Microsoft Media Server protocol traffic within Wireshark.

The core issue lies in improper length validation when processing MSMMS packets. When Wireshark encounters a specially crafted MSMMS packet, the dissector fails to adequately verify that the length field provided in the packet corresponds to the actual available buffer space. This missing validation allows an attacker to specify an arbitrary length value that exceeds the allocated heap buffer, resulting in a classic heap-based buffer overflow condition.

The vulnerability requires user interaction, specifically requiring a user to open a malicious capture file or analyze network traffic containing the crafted packets. Additionally, the vendor notes that an "unusual configuration" is required for successful exploitation, which may limit the attack surface in typical deployment scenarios.

Root Cause

The root cause is improper input validation in the MSMMS dissector code. The dissector trusts the length value provided in the MSMMS packet header without verifying that the specified length does not exceed the boundaries of the allocated heap buffer. This lack of bounds checking allows an attacker to write data beyond the intended buffer boundaries, corrupting adjacent heap memory.

Attack Vector

The attack vector is network-based but requires user interaction. An attacker could exploit this vulnerability through the following methods:

1. Malicious Capture File: Creating a specially crafted PCAP or PCAPNG file containing malicious MSMMS packets and convincing a user to open it in Wireshark
2. Live Traffic Analysis: If a user is capturing traffic from a network where the attacker can inject malicious packets, the MSMMS dissector would process the crafted packets

The vulnerability does not require authentication or special privileges to trigger, but does depend on the target user opening or processing the malicious traffic.

Detection Methods for CVE-2023-0667

Indicators of Compromise

• Unexpected Wireshark crashes during capture file analysis, particularly when MSMMS traffic is present
• Wireshark process consuming excessive memory or exhibiting unstable behavior when processing certain capture files
• Core dumps or crash reports pointing to heap corruption in the MSMMS dissector module

Detection Strategies

• Monitor for Wireshark process crashes that generate heap corruption signatures in crash dumps
• Implement file integrity monitoring on capture files before analysis in enterprise environments
• Deploy endpoint detection solutions that can identify heap spray and buffer overflow exploitation attempts

Monitoring Recommendations

• Review Wireshark application logs for dissector errors related to MSMMS protocol processing
• Implement centralized logging for forensic analysis workstations to detect unusual application behavior
• Configure alerting for repeated Wireshark crashes that may indicate exploitation attempts

How to Mitigate CVE-2023-0667

Immediate Actions Required

• Upgrade Wireshark to version 4.0.6 or later, which contains the fix for this vulnerability
• Disable the MSMMS dissector if not required using Analyze > Enabled Protocols and unchecking MSMMS
• Avoid opening capture files from untrusted sources until patches are applied
• Consider using Wireshark in a sandboxed or isolated environment when analyzing untrusted traffic

Patch Information

The vulnerability has been addressed by the Wireshark development team. Users should upgrade to the latest stable version of Wireshark. Security advisories have been released by multiple distributions including Gentoo GLSA 2023-09-02 and Debian LTS. Technical details about the fix can be found in the GitLab Issue Discussion.

Workarounds

• Disable the MSMMS protocol dissector through Wireshark's protocol preferences menu
• Use TShark with specific protocol filters that exclude MSMMS when processing untrusted captures
• Implement network segmentation to isolate analysis workstations from potentially hostile network traffic
• Process untrusted capture files in a disposable virtual machine environment

# Disable MSMMS dissector via command line
tshark -o "msmms.enabled:false" -r capture.pcap

# Alternative: Disable via Wireshark preferences file
# Add to ~/.config/wireshark/preferences (Linux) or %APPDATA%\Wireshark\preferences (Windows)
# msmms.enabled: FALSE