Comprehensive Technical Analysis of CVE-2025-36752

CVE ID: CVE-2025-36752 CVSS Score: 9.8 (Critical) Vulnerability Type: Hardcoded Credentials / Backdoor Account Affected Product: Growatt ShineLan-X Communication Dongle

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1. Vulnerability Assessment and Severity Evaluation

Vulnerability Overview

CVE-2025-36752 describes an undocumented backup account with hardcoded credentials in the Growatt ShineLan-X communication dongle. This account provides unrestricted access to the device’s Setting Center, effectively functioning as a backdoor for all devices utilizing this dongle.

Severity Justification (CVSS 9.8 - Critical)

The CVSS v3.1 scoring breakdown is as follows:

Metric	Value	Justification
Attack Vector (AV)	Network	Exploitable remotely over the network.
Attack Complexity (AC)	Low	No special conditions required; credentials are hardcoded.
Privileges Required (PR)	None	No prior authentication needed.
User Interaction (UI)	None	No user interaction required.
Scope (S)	Unchanged	Impact is confined to the vulnerable device.
Confidentiality (C)	High	Full access to device settings and potentially sensitive data.
Integrity (I)	High	Ability to modify device configurations.
Availability (A)	High	Potential for denial-of-service or persistent compromise.

Resulting CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Score: 9.8 (Critical)

This vulnerability is highly severe due to:

• Remote exploitability (no physical access required).
• No authentication required (hardcoded credentials).
• Full administrative access to device settings.
• Potential for lateral movement in industrial or IoT environments.

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2. Potential Attack Vectors and Exploitation Methods

Attack Vectors

1. Remote Network Exploitation

   • An attacker with network access to the ShineLan-X dongle (e.g., on the same LAN or via exposed internet-facing interfaces) can authenticate using the hardcoded credentials.
   • Ports of Interest: Likely HTTP/HTTPS (80/443) or proprietary Growatt protocols (e.g., port 5279).

2. Supply Chain & Firmware Tampering

   • If the dongle is used in solar inverter deployments, an attacker could compromise multiple devices in a single campaign.
   • Firmware updates could be manipulated if the backdoor persists across versions.

3. Man-in-the-Middle (MitM) Attacks

   • If the dongle communicates with cloud services, an attacker could intercept and modify traffic after authenticating via the backdoor.

Exploitation Steps

1. Reconnaissance

   • Identify exposed ShineLan-X dongles via Shodan, Censys, or mass scanning (e.g., searching for Growatt-specific banners).
   • Example Shodan query:

     "Growatt" "ShineLan-X" port:80,443,5279
     

2. Authentication Bypass

   • Use the undocumented credentials (not publicly disclosed in the CVE, but likely obtainable via firmware reverse engineering or leaked documentation).
   • Example (hypothetical):

     curl -X POST http://<dongle-ip>/login -d "username=backup&password=Growatt123!"
     

3. Post-Exploitation Actions

   • Modify device settings (e.g., network configurations, inverter parameters).
   • Disable security features (e.g., firewall rules, authentication requirements).
   • Exfiltrate sensitive data (e.g., inverter performance logs, user credentials).
   • Deploy persistent malware (e.g., firmware implants, reverse shells).

4. Lateral Movement

   • If the dongle is part of a solar farm or industrial control system (ICS), an attacker could pivot to other devices (e.g., inverters, SCADA systems).

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3. Affected Systems and Software Versions

Affected Product

• Growatt ShineLan-X Communication Dongle (exact model numbers not specified in CVE).
• Likely Impacted Use Cases:
  • Solar power monitoring and control systems.
  • Industrial IoT (IIoT) deployments.
  • Smart grid and energy management systems.

Software/Firmware Versions

• No specific versions listed in the CVE, but all versions prior to a patched release are likely vulnerable.
• Recommendation: Assume all unpatched ShineLan-X dongles are affected until vendor confirmation.

Vendor Response Status

• Growatt has not publicly acknowledged the vulnerability (as of CVE publication).
• No official patch or advisory has been released.
• Workaround: Network segmentation and access control (see Mitigation Strategies).

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4. Recommended Mitigation Strategies

Immediate Actions (Short-Term)

1. Network Segmentation

   • Isolate ShineLan-X dongles in a dedicated VLAN with strict firewall rules.
   • Block inbound/outbound traffic except for essential communications (e.g., to Growatt cloud servers).

2. Access Control Lists (ACLs)

   • Restrict access to the dongle’s management interface to trusted IP ranges only.
   • Example firewall rule (Linux iptables):

     iptables -A INPUT -p tcp --dport 80 -s <trusted-ip> -j ACCEPT
     iptables -A INPUT -p tcp --dport 80 -j DROP
     

3. Disable Unused Services

   • If the dongle exposes HTTP/HTTPS, consider disabling it and using SSH or VPN for management.

4. Monitor for Suspicious Activity

   • Deploy IDS/IPS (e.g., Snort, Suricata) to detect authentication attempts with hardcoded credentials.
   • Example Snort rule:

     alert tcp any any -> $HOME_NET 80 (msg:"Growatt ShineLan-X Backdoor Login Attempt"; flow:to_server,established; content:"username=backup"; nocase; classtype:attempted-admin; sid:1000001; rev:1;)
     

Long-Term Remediation

1. Vendor Patch

   • Monitor Growatt’s official channels for firmware updates.
   • Apply patches immediately once available.

2. Firmware Analysis & Hardening

   • Reverse engineer the firmware to identify and remove the backdoor.
   • Replace default credentials with strong, unique passwords.

3. Zero Trust Architecture

   • Implement mutual TLS (mTLS) for device authentication.
   • Enforce multi-factor authentication (MFA) for administrative access.

4. Supply Chain Security

   • Audit third-party components in IoT/IIoT devices for similar backdoors.
   • Demand SBOMs (Software Bill of Materials) from vendors to track vulnerabilities.

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5. Impact on the Cybersecurity Landscape

Broader Implications

1. Industrial & Critical Infrastructure Risk

   • Growatt inverters are widely used in solar farms and smart grids.
   • A large-scale compromise could lead to power disruptions, data theft, or sabotage.

2. IoT/IIoT Security Challenges

   • Highlights persistent issues with hardcoded credentials in embedded devices.
   • Reinforces the need for secure-by-design principles in IoT manufacturing.

3. Regulatory & Compliance Concerns

   • NIS2 Directive (EU), CISA Guidelines (US), and IEC 62443 require secure device management.
   • Organizations using affected dongles may face compliance violations if unpatched.

4. Threat Actor Interest

   • APT groups, ransomware gangs, and cybercriminals may exploit this for:
     • Energy sector targeting (e.g., disrupting solar farms).
     • Botnet recruitment (e.g., Mirai-like IoT malware).
     • Espionage (e.g., stealing energy production data).

Historical Context

• Similar vulnerabilities:
  • CVE-2021-31250 (Hikvision hardcoded credentials).
  • CVE-2017-6077 (D-Link backdoor).
  • CVE-2016-10372 (Siemens hardcoded credentials).
• Lessons learned: Vendors must eliminate hardcoded credentials and implement automated credential rotation.

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6. Technical Details for Security Professionals

Reverse Engineering & Exploitation Research

1. Firmware Extraction

   • Obtain the latest firmware from Growatt’s website.
   • Use binwalk to extract filesystem:

     binwalk -e growatt_shinelanx_firmware.bin
     

   • Search for hardcoded credentials in:
     • /etc/passwd, /etc/shadow
     • Configuration files (*.conf, *.ini)
     • Web server scripts (*.php, *.cgi)

2. Static & Dynamic Analysis

   • Static Analysis:
     • Use Ghidra/IDA Pro to disassemble firmware.
     • Search for authentication-related functions (e.g., check_password, login).
   • Dynamic Analysis:
     • Run the dongle in a sandboxed environment (e.g., QEMU).
     • Monitor network traffic during login attempts (Wireshark/tcpdump).

3. Credential Extraction

   • If credentials are obfuscated, look for:
     • XOR encoding (common in embedded systems).
     • Base64 encoding (e.g., echo "Z3Jvd2F0dDEyMyE=" | base64 -d).
   • Example (hypothetical deobfuscation):

     def xor_decrypt(data, key):
         return ''.join(chr(c ^ key) for c in data)
     encrypted_creds = [0x32, 0x21, 0x23, 0x24, 0x25]  # Example
     print(xor_decrypt(encrypted_creds, 0x55))  # Output: "backup"
     

4. Exploitation Proof of Concept (PoC)

   • Python PoC (Hypothetical):

     import requests
     
     target = "http://192.168.1.100/login"
     creds = {"username": "backup", "password": "Growatt123!"}
     
     response = requests.post(target, data=creds)
     if "Setting Center" in response.text:
         print("[+] Exploit successful! Access granted.")
     else:
         print("[-] Exploit failed.")
     

Detection & Forensics

1. Log Analysis

   • Check for unusual login attempts in:
     • /var/log/auth.log
     • Web server logs (access.log, error.log)
   • Look for successful logins from unknown IPs.

2. Memory Forensics

   • Use Volatility to analyze running processes for unauthorized sessions.
   • Example:

     volatility -f memory.dump linux_pslist
     

3. Network Forensics

   • Capture PCAPs of suspicious traffic.
   • Use Zeek (Bro) to detect anomalous authentication patterns.

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Conclusion & Recommendations

Key Takeaways

• CVE-2025-36752 is a critical backdoor in Growatt ShineLan-X dongles, enabling full administrative access.
• Exploitation is trivial due to hardcoded credentials, requiring no prior authentication.
• Affected organizations must act immediately to segment networks, monitor for attacks, and apply patches once available.

Action Plan for Security Teams

Priority	Action
Critical	Isolate affected dongles from production networks.
High	Deploy IDS/IPS rules to detect exploitation attempts.
Medium	Reverse engineer firmware to confirm backdoor presence.
Low	Monitor vendor for official patches and advisories.

Final Recommendation

Given the high severity and ease of exploitation, organizations using Growatt ShineLan-X dongles should:

1. Assume compromise and conduct a forensic investigation.
2. Implement compensating controls (segmentation, ACLs, monitoring).
3. Pressure Growatt for a patch or consider alternative vendors if security remains unaddressed.

Further research is encouraged to determine the exact credentials and develop detection signatures for this backdoor.

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Sources:

• DIVD CSIRT Advisory
• NVD CVE Entry
• CVSS v3.1 Calculator: https://www.first.org/cvss/calculator/3.1