The OWASP Top 10 2021 update highlights injection vulnerabilities, now including Cross-site Scripting (XSS), as the most prevalent security threat, though it has moved to third place. Injection vulnerabilities, particularly SQL injection, occur when untrusted data is sent to an interpreter, often found in database queries and other commands, posing significant risks such as data theft or system takeover. The text discusses the widespread nature of these vulnerabilities, especially in legacy systems, and notes that even major corporations like Sony and MySQL have faced attacks. Detecting these vulnerabilities can be challenging without visible feedback, but automated security tools like Detectify can help identify over 700 vulnerabilities, including those in the OWASP Top 10. Remediation strategies include using parameterized queries or carefully escaping special characters to prevent exploits, as exemplified in a code snippet illustrating a typical SQL injection scenario.