CVE-2025-69727: PRONOTE Auth Bypass Vulnerability

CVE-2025-69727 Overview

An Incorrect Access Control vulnerability exists in INDEX-EDUCATION PRONOTE prior to version 2025.2.8. The affected components (index.js and composeUrlImgPhotoIndividu) allow the construction of direct URLs to user profile images based solely on predictable identifiers such as user IDs and names. Due to missing authorization checks and lack of rate-limiting when generating or accessing these URLs, an unauthenticated or unauthorized actor may retrieve profile pictures of users by crafting requests with guessed or known identifiers.

Critical Impact

This vulnerability enables unauthorized access to user profile images in PRONOTE, an educational management platform, potentially exposing personal photographs of students and staff members without authentication.

Affected Products

• INDEX-EDUCATION PRONOTE versions prior to 2025.2.8

Discovery Timeline

• 2026-03-16 - CVE CVE-2025-69727 published to NVD
• 2026-03-17 - Last updated in NVD database

Technical Details for CVE-2025-69727

Vulnerability Analysis

This vulnerability stems from a broken access control implementation within the PRONOTE educational management platform. The application constructs URLs for user profile images using predictable identifiers—specifically user IDs and names—without implementing proper authorization verification. When a request is made to retrieve a profile image, the application fails to validate whether the requesting party has legitimate access to view that particular user's photograph.

The affected components index.js and composeUrlImgPhotoIndividu are responsible for URL generation and image retrieval functionality. The lack of authentication requirements combined with the absence of rate-limiting mechanisms creates an environment where attackers can systematically enumerate and harvest user profile images by iterating through predictable identifier patterns.

This type of Insecure Direct Object Reference (IDOR) vulnerability is particularly concerning in educational contexts where the exposed images may include photographs of minors.

Root Cause

The root cause of this vulnerability is the absence of proper authorization checks in the image retrieval functionality. The application relies solely on knowledge of predictable identifiers (user IDs and names) to grant access to profile images, rather than implementing session-based authentication or access control lists. Additionally, the missing rate-limiting mechanism allows attackers to perform enumeration attacks without triggering protective countermeasures.

Attack Vector

The vulnerability is exploitable over the network without requiring any authentication or user interaction. An attacker can craft HTTP requests targeting the image URL endpoints by guessing or obtaining user identifiers. The predictable nature of these identifiers (sequential IDs, common names) makes enumeration attacks feasible.

The attack flow involves:

1. Identifying the URL pattern used by the composeUrlImgPhotoIndividu function
2. Generating requests with incremented user IDs or known usernames
3. Harvesting returned profile images without authentication
4. Repeating the process without rate-limiting restrictions

Technical details and proof-of-concept information can be found in the GitHub PoC repository for CVE-2025-69727.

Detection Methods for CVE-2025-69727

Indicators of Compromise

• Unusual volume of requests to profile image endpoints from single IP addresses
• Sequential or pattern-based access attempts to user image URLs
• Requests for profile images without valid session tokens or authentication headers
• High rate of 200 OK responses to image endpoints from unauthenticated sources

Detection Strategies

• Implement logging and alerting for image endpoint access patterns that indicate enumeration attempts
• Monitor for requests accessing profile images without corresponding authenticated session activity
• Configure web application firewalls to detect and block sequential ID enumeration patterns
• Review access logs for requests containing incremental user identifiers in image URL parameters

Monitoring Recommendations

• Enable detailed logging on all endpoints handling profile image requests
• Set up alerts for unusual spikes in image retrieval requests from individual IP addresses
• Monitor authentication bypass attempts and correlate with image endpoint access
• Implement anomaly detection for access patterns that deviate from normal user behavior

How to Mitigate CVE-2025-69727

Immediate Actions Required

• Upgrade INDEX-EDUCATION PRONOTE to version 2025.2.8 or later immediately
• Implement authentication requirements for all profile image endpoints as a temporary measure
• Enable rate-limiting on image retrieval functionality to prevent enumeration attacks
• Review access logs to identify potential exploitation attempts and affected user accounts

Patch Information

INDEX-EDUCATION has addressed this vulnerability in PRONOTE version 2025.2.8. Organizations should prioritize upgrading to this version or later to remediate the incorrect access control issue. Refer to the Index Education Demo Portal for additional vendor information.

Workarounds

• Implement web application firewall rules to require authentication for profile image endpoints
• Deploy rate-limiting at the reverse proxy or load balancer level for image retrieval paths
• Use non-predictable, randomized tokens for image URLs instead of user IDs
• Restrict access to profile images through network segmentation until patching is possible
• Consider temporarily disabling profile image functionality if exploitation risk is deemed critical

# Example nginx rate-limiting configuration for image endpoints
limit_req_zone $binary_remote_addr zone=images:10m rate=10r/s;

location /photo/ {
    limit_req zone=images burst=20 nodelay;
    auth_basic "Restricted Access";
    auth_basic_user_file /etc/nginx/.htpasswd;
    # Additional authentication proxy configuration
}