Missing input source validation in the tool authorization prompt of Kiro CLI enables a local attacker to pipe arbitrary content to the application, resulting in the execution of any tool or shell command without user approval. The weakness is an authorization bypass that allows the attacker to run code with the privileges of the CLI user. This can compromise system integrity, leak confidential data, or serve as a foothold for further attacks.

AWS Kiro CLI versions prior to 1.28.0 are vulnerable. Users running any older release of the CLI may be exposed to this behavior.

The vulnerability has a CVSS score of 8.4, indicating high severity. EPSS data is unavailable, but the attack requires local access and the ability to pipe data to standard input, making it a local resource-based exploit. It is not listed in the CISA KEV catalog, suggesting no confirmed widespread exploitation yet.