CAS-005 Exam Dumps : CompTIA SecurityX Certification Exam

Removing unnecessary services from existing endpoints reduces the attack surface by minimizing the number of potential vulnerabilities attackers could exploit. This is a cost-effective method to harden devices without requiring new purchases, aligning perfectly with a purchasing freeze. Deploying new EDR solutions or disposing of devices would likely conflict with the resource freeze, and reimaging systems does not address minimizing services proactively.

The “cipher unavailable” message indicates that the client and server could not agree on a common cipher suite. After the OpenSSL update, the server likely dropped support for older, insecure ciphers (such as RC4 or 3DES) that legacy clients still use. The safest remediation is to update or configure the client applications to support modern, secure ciphers such as AES in Galois/Counter Mode (AES-GCM) or an equivalent strong cipher suite that is supported by the updated OpenSSL server.

Option A (SSL 3.0) is unsafe because SSL 3.0 is deprecated and vulnerable to multiple attacks (e.g., POODLE).

Option C (ECB mode) is insecure due to pattern leakage and should never be enforced.

Option D (ECC signatures) relates to key exchange and signatures, not to the “cipher unavailable” issue directly.

This approach aligns with SecurityX CAS-005 cryptographic interoperability guidance—modernize clients rather than reintroduce insecure protocols.

The most likely explanation for the issues encountered with the captive portal is that the TLS ciphers supported by the captive portal are deprecated. Here’s why:

TLS Cipher Suites: Modern browsers are continuously updated to support the latest security standards and often drop support for deprecated and insecure cipher suites. If the captive portal uses outdated TLS ciphers, newer browsers may refuse to connect, causing security errors.

HSTS and Browser Security: Browsers with HTTP Strict Transport Security (HSTS) enabled will not allow connections to sites with weak security configurations. Deprecated TLS ciphers would cause these browsers to block the connection.