The vulnerability stems from improper argument sanitization in multiple components. The commit diff shows critical fixes: 1) Added parameter count validation in Runner to prevent argument injection during templating (CVE-2014-4967 example #1-3). 2) Replaced unsafe string concatenation in action plugins with structured argument merging. 3) Replaced regex-based parsing in the command module with shlex splitting. These changes directly correlate to the described injection vectors (src=, temp=, validate= clauses). The affected functions handled user-controlled input without proper validation, allowing attackers to inject malicious parameters into command execution contexts.