Security Posture & Third-Party Tech-Stack

Scope

Two related lenses on a target:

Security posture — HTTP security headers, Content Security Policy, HSTS, email auth (SPF/DKIM/DMARC/MTA-STS), security.txt, certificate practices.
Third-party / SaaS detection — payment processors, analytics, customer support, identity providers, CRM/marketing, error monitoring, A/B testing, social/communication SDKs, media CDNs.

The two are coupled: CSP script-src and DNS TXT verifications reveal third-party services, while third-party domains contribute to the overall security surface.

Signals (input)

HTTP response headers — security headers, CSP directives, HSTS
DNS TXT records — SPF, DKIM, DMARC, SaaS verification tokens
HTML — meta-tag security policies, embedded widgets/iframes
Loaded JS / script-src URLs and globals
/.well-known/security.txt, /security.txt, /.well-known/change-password

Inferences (output)

Security score (header coverage, CSP strength, email-auth strength, security.txt presence)
CSP analysis (unsafe-inline/eval issues, allowed third-party domains)
Email-auth grade (DMARC policy strength)
Third-party SaaS catalogue by category, with integration mode (client SDK vs CSP-only vs DNS-only)

Techniques

See reference/patterns.md [blocked].

When to use

Pre-engagement security baseline
Mapping supply-chain / SaaS exposure
Identifying integrations that grant pivot opportunities (Auth0, Stripe webhook surface, Sentry DSN leakage, etc.)
Phase 3 of tech-stack OSINT