Executive Summary

CVE-2026-8276 is a remote denial-of-service (DoS) vulnerability in the MySQL server component of bettercap up to version 2.41.5. It occurs due to improper handling of client handshake packets, specifically when a crafted packet with certain capability flags causes the code to access an out-of-range index in a binary string representation of these flags. This leads to a runtime panic and crashes the entire bettercap process.

The root cause is that the code formats capability flags as an 8-bit binary string but then attempts to access the 9th character (index 8), which does not exist, causing an index-out-of-range error. Additionally, there was no proper validation of the handshake packet length before parsing, allowing malformed or truncated packets to trigger the crash.

The vulnerability can be exploited remotely by an unauthenticated attacker sending a specially crafted MySQL client handshake packet, and the attack requires a high level of complexity.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability can cause a remote denial-of-service (DoS) condition by crashing the entire bettercap process when it receives a maliciously crafted MySQL client handshake packet.

As a result, any services or operations relying on bettercap's MySQL server component may become unavailable or interrupted, potentially impacting system stability and availability.

Since the attack can be launched remotely without authentication, it poses a risk of disruption from external attackers on the network.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by monitoring for unusual crashes or denial-of-service events in the bettercap process, specifically related to the MySQL server module. Since the exploit involves sending a specially crafted MySQL client handshake packet with a capability flags byte set to 0x00, network traffic analysis tools can be used to detect such malformed handshake packets.

A practical approach is to capture and inspect MySQL handshake packets on the network using packet capture tools like tcpdump or Wireshark, filtering for packets with unusual or malformed capability flags.

• Use tcpdump to capture MySQL handshake packets: tcpdump -i <interface> 'tcp port 3306 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) > 0)' -w capture.pcap
• Analyze the captured packets in Wireshark, looking for handshake packets with capability flags byte set to 0x00 or packets shorter than 37 bytes.

Additionally, monitoring bettercap logs or system logs for unexpected crashes or panics related to mysql_server.go can help detect exploitation attempts.

Useful 0 Not Useful 0

Mitigation Strategies

The immediate mitigation step is to apply the patch identified as commit 0eaa375c5e5446bfba94a290eff92967a5deac9e which fixes the vulnerability by adding validation checks on the handshake packet length and correcting the parsing of client capability flags.

Until the patch is applied, consider restricting access to the bettercap MySQL server component from untrusted or unauthenticated clients to reduce the risk of remote exploitation.

Monitoring and alerting on unexpected bettercap process crashes can also help in early detection of exploitation attempts.

Useful 0 Not Useful 0

Compliance Impact

The provided information does not include any details about the impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.

Useful 0 Not Useful 0