CVE-2021-39409

CRITICAL

Online Student Rate System v1.0 - Auth Bypass

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2021-39409. PoCs published by StefanDorresteijn.

AI-analyzed exploit summary This repository contains a functional proof-of-concept for CVE-2021-39409, demonstrating an authentication bypass vulnerability in Online Student Rate System v1.0. The exploit allows an attacker to register an admin account by sending a crafted HTTP POST request with a specific `userLevelId` parameter.

Description

A vulnerability exists in Online Student Rate System v1.0 that allows any user to register as an administrator without needing to be authenticated.

Exploits (1)

nomisec WORKING POC
by StefanDorresteijn · poc
https://github.com/StefanDorresteijn/CVE-2021-39409

This repository contains a functional proof-of-concept for CVE-2021-39409, demonstrating an authentication bypass vulnerability in Online Student Rate System v1.0. The exploit allows an attacker to register an admin account by sending a crafted HTTP POST request with a specific `userLevelId` parameter.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Online Student Rate System v1.0
No auth needed
Prerequisites: Access to the target application's registration endpoint
devstral-2 · analyzed Feb 19, 2026 Full analysis →

References (1)

Core 1
Core References
Exploit, Third Party Advisory x_refsource_misc
https://github.com/StefanDorresteijn/CVE-2021-39409

Scores

CVSS v3 9.8
EPSS 0.0229
EPSS Percentile 81.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

Status published
Products (1)
online_student_rate_system_project/online_student_rate_system 1.0
Published Jun 24, 2022
Tracked Since Feb 18, 2026