Deep SSL/TLS Vulnerability Test
This report provides a deep analysis of the SSL/TLS configuration of stackoverflow.com. It checks for protocol support, cipher strength, and known vulnerabilities.
Scan Results
Start 2026-01-24 10:41:05 -->> 198.252.206.1:443 (stackoverflow.com) <<-- rDNS (198.252.206.1): stackoverflow.com. Service detected: HTTP Testing for server implementation bugs No bugs found. Testing HTTP header response @ "/" HTTP Status Code 302 Found, redirecting to "/questions" HTTP clock skew 0 sec from localtime IPv4 address in header Set-Cookie: __cf_bm=VVAo9IgiqnuvCArzeFs26fRTgtpRf91.QN5NfpMj1o8-1769251293-1.0.1.1-NTVr22ztRN4z41E1QNNyhRttlKYCsJOieqzv98Ok51jC8N9NVIM3xSDDuojgUF8FTXR7_EAZzpBemimNM8SwtsHILi_JjfVpQ0AbK7MHtj0; path=/; expires=Sat, 24-Jan-26 11:11:33 GMT; domain=.stackoverflow.com; HttpOnly; Secure; SameSite=None (check if it's your IP address or e.g. a cluster IP) Set-Cookie: _cfuvid=PwQlOYVBU2zGKFTz.tEqC_SaXQPW_j1SNNPoSqoJDE4-1769251293104-0.0.1.1-604800000; path=/; domain=.stackoverflow.com; HttpOnly; Secure; SameSite=None Strict Transport Security 365 days=31536000 s, includeSubDomains Public Key Pinning -- Server banner cloudflare Application banner -- Cookie(s) 5 issued: 3/5 secure, 5/5 HttpOnly -- maybe better try target URL of 30x Security headers X-Frame-Options: SAMEORIGIN Content-Security-Policy: upgrade-insecure-requests; frame-ancestors 'self' https://stackexchange.com Cache-Control: private 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=13F9CC06F3F1280D5C9EEFD646FC68EB00D6EA90C0DF915D39CFA196F13DFBD6 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 2026-01-24 10:41:48 [ 52s] -->> 198.252.206.1:443 (stackoverflow.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.