Deep SSL/TLS Vulnerability Test
This report provides a deep analysis of the SSL/TLS configuration of api.backlinko.com. It checks for protocol support, cipher strength, and known vulnerabilities.
Scan Results
Start 2026-10-10 21:42:03 -->> 162.159.135.42:443 (api.backlinko.com) <<-- rDNS (162.159.135.42): -- Service detected: HTTP Testing for server implementation bugs No bugs found. Testing HTTP header response @ "/" HTTP Status Code 301 Moved Permanently, redirecting to "https://backlinko.com" HTTP clock skew +28 sec from localtime HTTP Age (RFC 7234) 28 IPv4 address in header set-cookie: __cf_bm=4A_mCE.aQdpzG22Rziz9r4RqSalm8EnyAYgzCr4mNzw-1791668553.8317883-1.0.1.1-hkLsYUuuet1n36dFAFAenUJy7pMLJaPa3SzDbcwheNJAFo.CmTqERmKhkgmM6OleQFjFuBqORBIfPLyQR1h7DUekZsVCf8gpHOP51Hnd9vMR8xwsZ1Go80CcfDmMJpp6; HttpOnly; SameSite=None; Secure; Path=/; Domain=api.backlinko.com; Expires=Sat, 10 Oct 2026 22:12:33 GMT (check if it's your IP address or e.g. a cluster IP) Strict Transport Security not offered Public Key Pinning -- Server banner cloudflare Application banner -- Cookie(s) 1 issued: 1/1 secure, 1/1 HttpOnly -- maybe better try target URL of 30x Security headers X-Content-Type-Options: nosniff Cache-Control: public, max-age=0, s-maxage=900 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) no gzip/deflate/compress/br HTTP compression (OK) - only supplied "/" tested POODLE, SSL (CVE-2014-3566) not vulnerable (OK) TLS_FALLBACK_SCSV (RFC 7507) No fallback possible (OK), no protocol below TLS 1.2 offered SWEET32 (CVE-2016-2183, CVE-2016-6329) not vulnerable (OK) 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=98603085D95E292C4F4DA745F9CAC786EE54C3D7097DE8776032E0480E8AA0E3 LOGJAM (CVE-2015-4000), experimental not vulnerable (OK): no DH EXPORT ciphers, no DH key detected with <= TLS 1.2 BEAST (CVE-2011-3389) not vulnerable (OK), no SSL3 or TLS1 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 2026-10-10 21:42:48 [ 55s] -->> 162.159.135.42:443 (api.backlinko.com) <<--
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.