Bref Body Parsing Inconsistency in Event-Driven Functions

Vulnerability Description

Bref enable serverless PHP on AWS Lambda. When Bref is used with the Event-Driven Function runtime and the handler is a `RequestHandlerInterface`, then the Lambda event is converted to a PSR7 object. During the conversion process, if the request is a MultiPart, each part is parsed and its content added in the `$files` or `$parsedBody` arrays. The conversion process produces a different output compared to the one of plain PHP when keys ending with and open square bracket ([) are used. Based on the application logic the difference in the body parsing might lead to vulnerabilities and/or undefined behaviors. This vulnerability is patched in 2.1.13.

References

• https://github.com/brefphp/bref/security/advisories/GHSA-82vx-mm6r-gg8w
• https://github.com/brefphp/bref/commit/c77d9f5abf021f29fa96b5720b7b84adbd199092