CVE-2025-26702

Executive Summary

CVE-2025-26702 is an Improper Input Validation vulnerability in ZTE GoldenDB, a distributed database product. The flaw allows an unauthenticated attacker to manipulate input data, potentially leading to data integrity breaches. With a CVSS score of 4.9 (Medium), the vulnerability affects GoldenDB versions 6.1.03 through 6.1.03.04. No public exploit code or patch is currently available, but the risk is elevated due to the lack of vendor remediation. The vulnerability is classified under MITRE Tactic T1190 (Exploit Public-Facing Application) and CWE-20 (Improper Input Validation). No supply chain or package security concerns are identified as this is a proprietary database product.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
• Base Score: 4.9 (Medium)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Impact confined to the vulnerable component.
• Confidentiality Impact: None (C:N) – No data disclosure.
• Integrity Impact: Low (I:L) – Limited data manipulation possible.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. The low EPSS score (0.0%) suggests limited active exploitation, but the lack of a patch and the potential for data manipulation in a database product warrant attention.

Deep Dive & Mechanics

The vulnerability stems from improper validation of user-supplied input within ZTE GoldenDB. Specifically, the software fails to sanitize or verify data before processing it, allowing an attacker to inject malicious input that can alter database operations. This could lead to unauthorized modification of data, such as inserting, updating, or deleting records without proper authorization.

Attack Vector: The attacker sends specially crafted network requests to the GoldenDB service (typically listening on port 3306 for MySQL-compatible protocols). By manipulating SQL queries or other input fields, the attacker can bypass input validation checks.

Impact: While the CVSS indicates low integrity impact, in a database context, even limited data manipulation can have cascading effects, such as corrupting financial records, altering user permissions, or injecting malicious data that triggers further exploits.

Affected Versions: GoldenDB 6.1.03 through 6.1.03.04. No patch is available as of the advisory date.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison is not possible. However, the vulnerability likely involves missing input validation in functions that handle user input, such as SQL query parsers or API endpoints.

Vulnerable Code Pattern (Hypothetical):

def process_input(user_input):
    # No validation
    query = "SELECT * FROM users WHERE id = " + user_input
    execute_query(query)

Patched Code Pattern (Expected):

def process_input(user_input):
    # Validate input
    if not user_input.isdigit():
        raise ValueError("Invalid input")
    query = "SELECT * FROM users WHERE id = " + user_input
    execute_query(query)

The fix would involve implementing strict input validation, parameterized queries, or whitelisting allowed characters.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Access to a vulnerable GoldenDB instance (version 6.1.03 to 6.1.03.04).
• Network connectivity to the database port (default 3306).

Exploitation Steps:

1. Reconnaissance: Scan for GoldenDB instances using Shodan dorks or port scanning.
2. Identify Vulnerability: Send crafted input to the database service to test for improper validation.
3. Exploit: Use a tool like mysql client or custom script to inject malicious data.

Example Payload (Hypothetical):

-- Attempt to manipulate data via injection
INSERT INTO users (username, role) VALUES ('attacker', 'admin');

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor for unusual SQL queries or data manipulation attempts.
• Use network intrusion detection systems (NIDS) to flag suspicious patterns.

Mitigation:

• Apply network segmentation to limit access to GoldenDB.
• Implement web application firewalls (WAF) to filter malicious input.
• Monitor logs for anomalies in database operations.

Indicators of Compromise (IOCs)

• Network Traffic: Unusual SQL queries containing unexpected characters or commands.
• Log Entries: Failed authentication attempts followed by successful data manipulation.
• File Changes: Unexpected modifications to database tables or records.
• Process Anomalies: GoldenDB processes consuming abnormal resources.

Example IOC (Hypothetical):

{
  "type": "network",
  "source_ip": "192.168.1.100",
  "destination_port": 3306,
  "payload": "INSERT INTO users (username, role) VALUES ('attacker', 'admin')"
}

Detection Engineering

YARA Rule

rule CVE_2025_26702_GoldenDB_Input_Validation {
    meta:
        description = "Detects attempts to exploit CVE-2025-26702 in ZTE GoldenDB"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-26702"
    strings:
        $sql_injection = /INSERT\s+INTO\s+\w+\s+\(.*\)\s+VALUES\s+\(.*\)/ nocase
        $malicious_input = /[;'\"]\s*--/ nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-26702 GoldenDB Input Validation Exploit
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL injection attempts targeting ZTE GoldenDB
author: Valters IT
logsource:
    category: application
    product: goldenDB
detection:
    selection:
        query|contains:
            - "INSERT INTO"
            - "UPDATE"
            - "DELETE"
        query|re: "[';]--"
    condition: selection
falsepositives:
    - Legitimate database administration
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 3306 (msg:"CVE-2025-26702 GoldenDB Input Validation Attempt"; flow:to_server,established; content:"INSERT INTO"; nocase; content:"VALUES"; nocase; pcre:"/[';]--/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate Affected Systems: Restrict network access to GoldenDB instances using firewalls or network segmentation.
2. Monitor Logs: Enable detailed logging and review for suspicious activity.
3. Apply Workarounds: If possible, implement input validation at the application layer or use a reverse proxy to filter malicious requests.

Long-Term Fix:

• Await an official patch from ZTE. Contact ZTE support for updates.
• Consider upgrading to a patched version once released.
• Implement parameterized queries and strict input validation in all database interactions.

Valters IT Signature

This report is provided for educational and defensive purposes only. Unauthorized exploitation of this vulnerability is illegal.