The Security of Ephemeral Pages
3 days ago
- #Web Security
- #Vulnerability Mitigation
- #AI Review
- Ephemeral Pages faced critical security vulnerabilities identified through AI agent review, primarily involving same-origin XSS risks from direct HTML serving.
- Mitigations included adding HTTP headers like Content-Security-Policy with sandboxing, rate limiting for uploads and abuse reports, and securing admin delete tokens.
- Medium vulnerabilities addressed rate limiting using hashed actor and subject data with time-bound records, and cross-origin URL validation for admin reviews.
- Low-level hardening implemented site-wide security headers, tightened HTML validation with parse5 library, and constant-time comparison for token checks.
- The review process enhanced app robustness, though some risks like direct string comparison for tokens were accepted as calculated trade-offs.