Security+ application vulnerabilities: follow the trust boundary
Injection vulnerabilities let untrusted input influence a command or query structure. Cross-site scripting puts attacker-controlled script into another user browser context. Unsafe memory handling can corrupt program state, while a race condition depends on timing between operations. Identify the boundary the application failed to enforce before choosing a vulnerability label or a mitigation.
How to read the scenario
One generic input filter is not a complete application-security design. Use context-appropriate controls, such as parameterized database queries and safe output encoding.
Identify the required outcome, the evidence already provided, and the limits on the technician’s action. Compare every option against those details before deciding. Record why the closest alternative does not meet the stated need.
Original practice example
An application writes attacker-controlled input past the end of a fixed-size memory buffer. Which vulnerability class is present?
- SQL injection vulnerability
- Cross-site scripting vulnerability
- Race condition
- Buffer overflow
Show the answer and explanation
Buffer overflow
A buffer overflow writes beyond allocated memory and can corrupt program state.
Study questions
Which objective does this guide support?
SY0-701, objective 2.3. This independent guide supports original practice and does not replace the full official objectives.
What should I watch for in a scenario?
One generic input filter is not a complete application-security design. Use context-appropriate controls, such as parameterized database queries and safe output encoding.
Source and version
CompTIA official SY0-701 objectives, objective 2.3. Verified November 5, 2026. This guide targets SY0-701. SY0-801 is expected around November 17, 2026 and is outside this edition.