CVE-2021-41773 PoC — Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

Source

https://github.com/iosifache/ApacheRCEEssay

Associated Vulnerability

Title:Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 (CVE-2021-41773)
Description:A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

Description

Essay (and PoCs) about CVE-2021-41773, a remote code execution vulnerability in Apache 2.4.49 🕸️

Readme

# CVE-2021-41773 Essay 🕸️

## Description 🖼️

This repository contains an essay about CVE-2021-41773, a remote code execution vulnerability in Apache 2.4.49. This was created for a course from Faculty of Automatic Control and Computers, University POLITEHNICA of Bucharest, namely "*Cyberdefences and Cyberintelligence*".

## Folders Structure 📁

The folder structure is as follows:
- **[`demo`](demo)**: A proof of concept consisting in a Docker Compose architecture with two container: a vulnerable web server and an attacker having a Python exploit script  
- **[`document`](document)**: The LaTeX project and the exported document.
- **[`presentation`](presentation)**: The LaTeX project and the exported presentation.

## Preview 👀

| Document                                                                                                           | Presentation                                                                                                                   |
| ------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------ |
| <a href="document/export.pdf"><kbd><img src="document/preview.png" width="400px" alt="Document preview"></kbd></a> | <a href="presentation/export.pdf"><kbd><img src="presentation/preview.png" width="400px" alt="Presentation preview"></kbd></a> |

File Snapshot


 [4.0K]  /data/pocs/b8f240a3536974044aea5a67d43d670ebc24fc78
├── [4.0K]  demo
│   ├── [4.0K]  attacker
│   │   ├── [ 122]  Dockerfile
│   │   └── [ 443]  exploit.sh
│   ├── [ 233]  docker-compose.yaml
│   ├── [ 737]  README.md
│   └── [4.0K]  server
├── [4.0K]  document
│   ├── [ 78K]  export.pdf
│   ├── [406K]  preview.png
│   └── [4.0K]  project
│       ├── [2.0K]  bibliography.bib
│       ├── [275K]  IEEEtran.cls
│       └── [7.5K]  main.tex
├── [4.0K]  presentation
│   ├── [126K]  export.pdf
│   ├── [ 35K]  preview.png
│   └── [4.0K]  project
│       ├── [ 574]  configuration.tex
│       ├── [4.0K]  images
│       │   └── [7.2K]  acs.jpg
│       ├── [2.6K]  main.sty
│       └── [2.8K]  main.tex
├── [1.5K]  README.md
└── [ 373]  update_previews.sh

8 directories, 17 files

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