CVE-2021-42669

CRITICAL

Engineers Online Portal - Unrestricted File Upload via Teacher Avatar Change

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2021-42669. PoCs published by 0xDeku.

AI-analyzed exploit summary This PoC exploits an unrestricted file upload vulnerability in the Engineers Online Portal system (CVE-2021-42669) to achieve remote code execution by uploading a PHP webshell. The exploit authenticates with provided credentials and uploads a malicious PHP file to the vulnerable endpoint.

Description

A file upload vulnerability exists in Sourcecodester Engineers Online Portal in PHP via dashboard_teacher.php, which allows changing the avatar through teacher_avatar.php. Once an avatar gets uploaded it is getting uploaded to the /admin/uploads/ directory, and is accessible by all users. By uploading a php webshell containing "<?php system($_GET["cmd"]); ?>" the attacker can execute commands on the web server with - /admin/uploads/php-webshell?cmd=id.

Exploits (2)

nomisec WORKING POC 2 stars
by 0xDeku · poc
https://github.com/0xDeku/CVE-2021-42669

This PoC exploits an unrestricted file upload vulnerability in the Engineers Online Portal system (CVE-2021-42669) to achieve remote code execution by uploading a PHP webshell. The exploit authenticates with provided credentials and uploads a malicious PHP file to the vulnerable endpoint.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Engineers Online Portal system (specific version not specified)
Auth required
Prerequisites: Valid credentials for the target system · Network access to the target web application
devstral-2 · analyzed Feb 16, 2026 Full analysis →
inthewild WORKING POC
poc
https://github.com/thehackingrabbi/cve-2021-42669

The repository contains a functional exploit for CVE-2021-42669, which leverages an unrestricted file upload vulnerability in the Engineers Online Portal system to achieve remote code execution. The exploit authenticates with provided credentials, uploads a PHP webshell, and provides a URL to access the shell.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Engineers Online Portal system
Auth required
Prerequisites: valid username and password for the target system · access to the login and file upload endpoints
devstral-2 · analyzed Feb 23, 2026 Full analysis →

References (3)

Core 3
Core References
Product, Third Party Advisory x_refsource_misc
https://www.sourcecodester.com/php/13115/engineers-online-portal-php.html
Exploit, Third Party Advisory x_refsource_misc
https://github.com/TheHackingRabbi/CVE-2021-42669
Exploit, Third Party Advisory x_refsource_misc
https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-42671

Scores

CVSS v3 9.8
EPSS 0.4422
EPSS Percentile 97.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-434
Status published
Products (1)
engineers_online_portal_project/engineers_online_portal
Published Nov 05, 2021
Tracked Since Feb 18, 2026