The RSA Conference 2024 was a hotspot for cybersecurity advancements, discussions, and key insights from industry leaders. Among the numerous topics covered, Tanya Janca (Head of Education and Community at Semgrep) and security researcher Scott Helme delivered a compelling talk on web application security headers and their critical role in protecting online assets.
Their presentation provided deep insights into HTTP security headers, how they function as the first line of defense against web-based attacks, and common misconceptions that prevent organizations from implementing them effectively. Below, we’ll break down the key topics they covered and why these headers are essential in modern cybersecurity.
Security Headers: The Seatbelts of Web Security
Janca used an interesting analogy, likening security headers to seatbelts. Just as a seatbelt protects passengers in the event of a crash, security headers safeguard websites when cyberattacks occur. Without them, web applications are left vulnerable to various exploits.
Helme reinforced this by explaining how different security headers function as protective mechanisms against common web vulnerabilities such as man-in-the-middle attacks, cross-site scripting (XSS), and cookie hijacking.
HSTS (HTTP Strict Transport Security) – The HTTPS Enforcer
One of the primary headers discussed was HSTS (HTTP Strict Transport Security), which ensures all website traffic is automatically redirected from HTTP to HTTPS, eliminating the possibility of an attacker intercepting unencrypted traffic.

What Can Go Wrong Without HSTS?
Without HSTS, several security risks emerge, including:
- Man-in-the-middle (MITM) attacks – Attackers can intercept and modify unencrypted data.
- Sensitive data exposure – User credentials and confidential data can be stolen.
- Data integrity issues – An attacker may alter transmitted content, injecting malicious code or misinformation.
- Cookie hijacking – Session cookies can be stolen if transmitted over an insecure connection.
Janca also pointed out that the images used in their presentation were AI-generated, showcasing how artificial intelligence is influencing even cybersecurity education and conference visuals.
CSP (Content Security Policy) – The Swiss Army Knife of Web Security
Helme used the analogy of a Swiss Army knife to describe Content Security Policy (CSP) because it offers a variety of tools to mitigate attacks like XSS, cookie stealing, and keyloggers.
Without a strong CSP implementation, attackers can exploit JavaScript vulnerabilities to:
- Inject malicious scripts (XSS attacks).
- Steal cookies and hijack user sessions.
- Install keyloggers to capture sensitive user inputs.
- Execute any action that JavaScript allows within a vulnerable website.

Common Misconceptions About Security Headers
Despite their effectiveness, many organizations hesitate to adopt security headers due to misconceptions, including:
- Header Conflicts – Belief that certain headers might contradict or interfere with each other.
- Lack of Consistency Across Browsers – Concerns over compatibility between different web browsers.
- Performance Hits – Fear that security headers will slow down websites.
- Maintenance and Updates – Worries about ongoing management efforts.
However, both Janca and Helme emphasized that the security benefits far outweigh these concerns. Modern browsers handle headers effectively, and performance impact is minimal compared to the severe risks of leaving applications unprotected.

Which Security Headers Should You Implement?
To build a robust security posture, the speakers recommended implementing several essential security headers, including:
- HSTS (HTTP Strict Transport Security) – Forces HTTPS connections.
- CSP (Content Security Policy) – Prevents unauthorized JavaScript execution.
- PP (Permission Policy) – Controls access to browser features like the camera and microphone.
- RP (Referrer Policy) – Limits the amount of information shared in the HTTP referrer header.
- XFO (X-Frame-Options) – Protects against clickjacking attacks.
- XCTO (X-Content-Type-Options) – Prevents MIME-type sniffing, reducing the risk of malicious file execution.
Additionally, they mentioned other lesser-known but equally important headers, such as:
- COEP (Cross-Origin Embedder Policy)
- COOP (Cross-Origin Opener Policy)
- CORP (Cross-Origin Resource Policy)
- CORB (Cross-Origin Read Blocking)
- CORS (Cross-Origin Resource Sharing)
These advanced headers help defend against side-channel attacks like Spectre and Meltdown, which exploit modern processors’ vulnerabilities.


Forbidden Headers: What NOT to Use
The speakers also addressed deprecated security headers that are either obsolete or potentially harmful, including:
- HTTP Public Key Pinning (HPKP) – Removed due to high risk of brick failures if misconfigured.
- X-XSS-Protection – Deprecated in favor of modern CSP-based protection.
- Expect-CT – No longer needed due to built-in browser security enhancements.
Final Thoughts: Are You Using Security Headers?
The key takeaway from their session was clear: Security headers are an essential, yet often overlooked, defense mechanism that every organization should implement. Much like wearing a seatbelt, they provide a simple but crucial layer of protection against a wide range of cyber threats.
As the cybersecurity landscape continues to evolve, staying informed and proactive is the best way to defend against modern attacks. Whether it’s adopting AI-driven security solutions, enforcing strict security headers, or debunking myths around web security, RSA 2024 highlighted that cyber resilience is more critical than ever.
For those looking to dive deeper, Janca and Helme provided a list of recommended security blogs, forums, and tools to stay updated in this fast-changing field.
Are your security headers up to date? If not, it’s time to implement them before the next attack strikes.