If when I evaluate the security readiness of a web server I find an issue in the code that might allow an SQL injection attack, what InfoSec term describes this development?

Vulnerability

Explanation:

Vulnerability is a cyber-security term that refers to a flaw in a system that can leave it open to attack. A vulnerability may also refer to any type of weakness in a computer system itself, in a set of procedures, or in anything that leaves information security exposed to a threat. Vulnerabilities are what information security and information assurance professionals seek to reduce. Cutting down vulnerabilities provides fewer options for malicious users to gain access to secure information.