Which of the following is a measure to protect against buffer overflows?

Patching and input validation are effective measures to protect against buffer overflows because buffer overflows typically occur when a program writes more data to a fixed-size block of memory (the buffer) than it was allocated. This can lead to unintended behavior, including crashes or execution of malicious code.

Patching involves updating software to fix known vulnerabilities, including those that could be exploited through buffer overflows. By regularly applying security patches, organizations can remediate these vulnerabilities before they can be exploited by attackers.

Input validation, on the other hand, is the process of ensuring that the input provided to a program meets certain criteria (such as length, type, or format) before it is processed. By validating input, applications can prevent excessive data from being entered into buffers, thereby reducing the risk of buffer overflows.

The other options, while relevant to different aspects of security, do not directly address the specific risks associated with buffer overflows. Firewalling and segmentation focus on network security, encryption and masking pertain to data confidentiality, and load balancing and backup are primarily concerned with performance and data availability.