Understanding Your Attack Surface: DNS, SSL, and Web Security

Your attack surface is the sum of all points where an unauthorized user could attempt to enter or extract data from your systems. It includes every domain, subdomain, IP address, open port, running service, and web endpoint that is reachable from the public internet.

• Domains and subdomains — including forgotten staging and dev environments
• IP addresses and open ports — every listener is a potential entry point
• SSL/TLS configurations — weak ciphers, expired certificates, protocol downgrades
• Web applications — missing security headers, exposed admin panels, verbose error pages

“Attackers don't break in through your front door — they find the side door you forgot existed. Shadow IT, forgotten subdomains, and legacy services are where most breaches begin.”

DNS enumeration is the foundation of attack surface mapping. By querying DNS records, you discover every subdomain, mail server, name server, and service endpoint associated with your domain — including ones you may have forgotten about.

Attackers routinely enumerate DNS as their first step in reconnaissance. If they find subdomains pointing to decommissioned servers, staging environments with default credentials, or internal services exposed to the public, they have an entry point.

• A/AAAA records — map domain names to IP addresses
• MX records — identify mail servers and their configurations
• NS records — reveal authoritative name servers
• TXT records — check for SPF, DKIM, and DMARC to prevent email spoofing
• CNAME records — detect dangling CNAMEs vulnerable to subdomain takeover
• Subdomain brute-force — discover hidden subdomains not in public records

A valid SSL certificate does not mean your TLS configuration is secure. Certificate validity is the bare minimum — real TLS security requires proper cipher suite selection, protocol version enforcement, certificate chain validation, and expiry monitoring.

“Over 30% of publicly reachable servers still support TLS 1.0 or 1.1, both of which have known vulnerabilities. A green padlock in the browser does not mean the connection is actually secure.”

• Certificate validation — hostname match, chain completeness, expiry date
• Protocol versions — ensure TLS 1.2+ only, no SSLv3/TLS 1.0/1.1
• Cipher suite analysis — identify weak ciphers (RC4, DES, export-grade)
• HSTS enforcement — verify HTTP Strict Transport Security is configured

Web security scanning examines the HTTP layer for misconfigurations and missing protections. Security headers are the first line of defense against common web attacks — and they are trivially easy to check, yet frequently missing.

• Content-Security-Policy (CSP) — prevents XSS and code injection
• X-Frame-Options — blocks clickjacking attacks
• X-Content-Type-Options — prevents MIME type sniffing
• Strict-Transport-Security (HSTS) — enforces HTTPS connections
• Server header disclosure — leaking web server version information
• Directory listing — exposing file structures to anyone who visits

Each missing header is a missed opportunity to prevent an entire class of attacks. Most can be added with a single configuration line — the cost of implementation is near zero, but the protection is significant.

Cystene scans all four dimensions — ports, DNS, SSL/TLS, and web security — in a single assessment. Instead of running separate tools for each check and manually correlating results, you get a unified view of your attack surface with prioritized findings ranked by severity.

• Four scan types running in parallel against your verified targets
• Unified findings with severity ratings from critical to informational
• Discovered assets mapped into a single infrastructure view
• Exportable reports for compliance reviews and stakeholder briefings

One scan. One dashboard. Your full attack surface. That's the Cystene approach — because your security posture should not depend on how many separate tools you can manage.