ISC2 CISSP Practice Question

The correct answer is dependency on vulnerabilities in the library that could affect the application. When incorporating third-party libraries, any security vulnerabilities in those libraries potentially extend to your application. If the library has flaws that allow injection attacks, buffer overflows, or other security issues, your application inherits those vulnerabilities, which can compromise the entire system regardless of how secure your custom code might be.

Inability to validate the cryptographic implementation within closed-source libraries is a legitimate security concern since cryptographic implementations can contain subtle flaws or weaknesses. However, this is a specific risk that applies primarily to security-focused libraries rather than a general risk that affects all third-party libraries.

Lack of control over the library's update and patch release cycle is a significant but secondary risk. While delayed security fixes can leave applications vulnerable for extended periods, the root issue remains the dependency on vulnerabilities in the libraries themselves, not just the timing of their remediation.

Possible inclusion of covert channels or backdoors in third-party code represents a supply chain security risk that applies mainly to libraries from untrusted or unvetted sources. While this is a serious concern in specific contexts, it's less common than unintentional vulnerabilities and usually mitigated through reputation, open-source scrutiny, or vendor assessment.