Episode 39 — Protect payment pages from skimming, injection, and tampering
Browser-based payment capture is a prime target for skimmers and injections, so the exam expects architecture and integrity controls that prevent untrusted code from accessing sensitive fields. This episode outlines a defensible baseline: isolate payment input using hosted fields or iFrames controlled by a validated provider, enforce Content Security Policy in blocking mode for scripts and connections, apply subresource integrity to fixed assets, and use controlled build pipelines that pin dependencies. Monitoring must detect unexpected DOM changes and outbound calls from checkout paths, and deployment must include pre-release integrity checks that catch accidental or malicious modifications. Evidence consists of server configurations, policy headers captured in tests, script inventories with hashes, and alert histories demonstrating detection of integrity violations.
We examine practical traps. A tag manager that injects third-party libraries on the checkout page can become an exfiltration path; strong answers restrict tag manager reach, require code reviews for any script touching payment routes, and isolate sensitive inputs so even loaded scripts cannot read PAN. A content delivery network serving cached JavaScript may deliver outdated or altered files; robust designs use immutable builds with versioned paths and verify content with subresource integrity on the client side. Troubleshooting addresses analytics that inadvertently collect form values, emergency hotfixes that bypass integrity checks, and browser extensions that interfere with rendering. The exam rewards options that reduce the number of components with access to payment fields, ensure only authorized code executes, and provide monitoring capable of catching tampering quickly, with artifacts that prove controls are both configured and effective during real operation. Produced by BareMetalCyber.com, where you’ll find more cyber audio courses, books, and information to strengthen your educational path. Also, if you want to stay up to date with the latest news, visit DailyCyber.News for a newsletter you can use, and a daily podcast you can commute with.
