Deep SSL/TLS Vulnerability Test
This report provides a deep analysis of the SSL/TLS configuration of recaptcha.net. It checks for protocol support, cipher strength, and known vulnerabilities.
Scan Results
Start 2026-05-22 17:55:30 -->> 173.194.206.94:443 (recaptcha.net) <<-- Further IP addresses: 2607:f8b0:4001:c62::5e rDNS (173.194.206.94): qj-in-f94.1e100.net. nz-in-f94.1e100.net. Service detected: HTTP Testing for server implementation bugs No bugs found. Testing HTTP header response @ "/" HTTP Status Code 404 Not Found (Hint: supply a path which doesn't give a "404 Not Found") HTTP clock skew 0 sec from localtime Strict Transport Security not offered Public Key Pinning -- Server banner ESF Application banner -- Cookie(s) (none issued at "/") -- HTTP status 404 signals you maybe missed the web application Security headers X-Content-Type-Options: nosniff X-XSS-Protection: 0 Cache-Control: no-cache, no-store, max-age=0, must-revalidate Pragma: no-cache Reverse Proxy banner -- Testing vulnerabilities Secure Renegotiation (RFC 5746) supported (OK) Secure Client-Initiated Renegotiation not vulnerable (OK) CRIME, TLS (CVE-2012-4929) not vulnerable (OK) BREACH (CVE-2013-3587) potentially NOT ok, "gzip" HTTP compression detected. - only supplied "/" tested Can be ignored for static pages or if no secrets in the page POODLE, SSL (CVE-2014-3566) not vulnerable (OK) TLS_FALLBACK_SCSV (RFC 7507) Downgrade attack prevention supported (OK) SWEET32 (CVE-2016-2183, CVE-2016-6329) VULNERABLE, uses 64 bit block ciphers FREAK (CVE-2015-0204) not vulnerable (OK) DROWN (CVE-2016-0800, CVE-2016-0703) not vulnerable on this host and port (OK) make sure you don't use this certificate elsewhere with SSLv2 enabled services, see https://search.censys.io/search?resource=hosts&virtual_hosts=INCLUDE&q=C46E833B4BB5C3AD82DD7F06AED4ADFCAF3FEE7B97C47F7326041D57BED4D8E4 LOGJAM (CVE-2015-4000), experimental not vulnerable (OK): no DH EXPORT ciphers, no DH key detected with <= TLS 1.2 BEAST (CVE-2011-3389) TLS1: ECDHE-ECDSA-AES128-SHA ECDHE-ECDSA-AES256-SHA ECDHE-RSA-AES128-SHA ECDHE-RSA-AES256-SHA AES128-SHA AES256-SHA DES-CBC3-SHA VULNERABLE -- but also supports higher protocols TLSv1.1 TLSv1.2 (likely mitigated) LUCKY13 (CVE-2013-0169), experimental potentially VULNERABLE, uses obsolete cipher block chaining ciphers with TLS, see server prefs. Winshock (CVE-2014-6321), experimental not vulnerable (OK) RC4 (CVE-2013-2566, CVE-2015-2808) no RC4 ciphers detected (OK) Done 2026-05-22 17:56:18 [ 57s] -->> 173.194.206.94:443 (recaptcha.net) <<--
About this Scan
This scan uses testssl.sh to check for:
- Protocols: SSLv2, SSLv3, TLS 1.0, TLS 1.1, TLS 1.2, TLS 1.3
- Vulnerabilities: Heartbleed, POODLE, FREAK, Logjam, DROWN, etc.
- Cipher Suites: Weak ciphers, perfect forward secrecy (PFS) support.