CVE-2023-49722

Executive Summary

CVE-2023-49722 exposes a critical security flaw in BCC101, BCC102, and BCC50 WiFi firmware. An open network port (8899) allows any attacker on the same WiFi network to connect to the device without authentication. This can lead to full device compromise, data exfiltration, or lateral movement within the network. The vulnerability has a CVSS score of 8.3 (High) and currently has no known patch or public exploit code. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk remains significant for exposed devices.

CVSS Breakdown & Threat Level

• CVSS Score: 8.3 (High)
• Attack Vector (AV): Adjacent Network (AV:A) – attacker must be on the same WiFi network.
• Attack Complexity (AC): Low (AC:L) – no special conditions required.
• Privileges Required (PR): None (PR:N) – no authentication needed.
• User Interaction (UI): None (UI:N) – no user action required.
• Scope (S): Unchanged (S:U) – the vulnerable component is the only one affected.
• Confidentiality (C): High (C:H) – full data access possible.
• Integrity (I): High (I:H) – full control over device data.
• Availability (A): High (A:H) – potential denial of service or device takeover.

Threat Level: High. The lack of authentication and the ability to connect from the same WiFi network make this a serious risk for any organization using these devices.

Deep Dive & Mechanics

The vulnerability stems from the WiFi firmware of BCC101, BCC102, and BCC50 devices exposing network port 8899. This port is likely used for device management, firmware updates, or debug interfaces. The firmware does not enforce any authentication or access control on this port, allowing any device on the same WiFi network to establish a connection.

Attack Scenario:

1. An attacker gains access to the same WiFi network (e.g., guest network, compromised credentials, or physical proximity).
2. The attacker scans for open port 8899 on the local subnet.
3. Upon discovery, the attacker connects to the port using a simple TCP client (e.g., netcat).
4. The device responds with a shell, management interface, or data stream, giving the attacker full control.

Potential Impact:

• Unauthorized access to device configuration and sensitive data.
• Ability to modify firmware or settings.
• Use of the device as a pivot point for further network attacks.
• Denial of service by sending malicious commands.

Vulnerable vs. Patched Code

No patched version exists. The vulnerable firmware is the only known version. The following pseudo-code illustrates the lack of authentication:

Vulnerable (current firmware):

// No authentication check
int main() {
    int server_fd = socket(AF_INET, SOCK_STREAM, 0);
    bind(server_fd, ...);
    listen(server_fd, 5);
    while (1) {
        int client_fd = accept(server_fd, NULL, NULL);
        // Directly handle client without authentication
        handle_client(client_fd);
    }
}

Patched (hypothetical):

int main() {
    int server_fd = socket(AF_INET, SOCK_STREAM, 0);
    bind(server_fd, ...);
    listen(server_fd, 5);
    while (1) {
        int client_fd = accept(server_fd, NULL, NULL);
        if (!authenticate(client_fd)) {
            close(client_fd);
            continue;
        }
        handle_client(client_fd);
    }
}

Exploitation & Lab Setup

Red Team (Attacker)

Lab Setup:

• Target: BCC101/BCC102/BCC50 device on the same WiFi network.
• Attacker machine: Kali Linux or any Linux with netcat.

Exploitation Steps:

1. Discover the device IP (e.g., via ARP scan):

   arp-scan --localnet
   

2. Connect to port 8899:

   nc <target_ip> 8899
   

3. If the port returns a shell or management interface, execute commands:

   # Example: list files
   ls -la
   # Example: download firmware
   cat /flash/firmware.bin
   

Note: No public exploit code exists; this is a manual exploitation scenario.

Blue Team (Defender)

Detection & Response:

• Monitor for connections to port 8899 from unknown devices.
• Use network segmentation to isolate these devices.
• Implement WiFi access controls (e.g., MAC filtering, 802.1X).
• Deploy honeypots mimicking the vulnerable port to detect scanning.

Hunting Queries:

• Search for devices with open port 8899 on the network.
• Look for unusual outbound connections from these devices.

Indicators of Compromise (IOCs)

• Network:
  • TCP connections to port 8899 on BCC devices.
  • Unusual data streams on port 8899 (e.g., shell commands).
• Host:
  • Unexpected processes or services running on the device.
  • Modified firmware or configuration files.
• Logs:
  • Firewall logs showing connections to port 8899 from non-admin IPs.
  • IDS/IPS alerts for port 8899 activity.

Detection Engineering

YARA Rule

rule CVE_2023_49722_BCC_Port8899 {
    meta:
        description = "Detects network traffic to BCC devices on port 8899"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-49722"
    strings:
        $port = "8899" ascii wide nocase
    condition:
        $port
}

Sigma Rule

title: Detection of BCC Device Port 8899 Connection
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects network connections to BCC devices on port 8899
author: Valters IT
date: 2025/04/10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2023-49722
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        DestinationPort: 8899
        DestinationIp|startswith: 
            - '192.168.'
            - '10.'
            - '172.16.'
    condition: selection
falsepositives:
    - Legitimate administrative access (if any)
level: high

Suricata Rule

alert tcp any any -> any 8899 (msg:"CVE-2023-49722 BCC Device Port 8899 Connection"; flow:to_server; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate devices: Place BCC101/BCC102/BCC50 on a separate VLAN with strict firewall rules blocking inbound connections to port 8899.
2. Disable WiFi if not needed: If the device can be used via Ethernet, disable WiFi to eliminate the attack vector.
3. Monitor network: Deploy IDS/IPS rules to detect port 8899 activity.

Long-term Fix:

• Contact BCC for a firmware update. If none is available, consider replacing the device with a secure alternative.
• Implement network access controls (NAC) to prevent unauthorized devices from connecting to the WiFi network.

Workaround:

• Use a firewall to block port 8899 at the network edge.
• Change the default WiFi password and use WPA3 if supported.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert