Potential URI resolution path traversal in the AWS SDK for PHP

Impact

Within the scope of requests to S3 object keys and/or prefixes containing a Unix double-dot, a URI path traversal is possible. The issue exists in thebuildEndpoint method in the RestSerializer component of the AWS SDK for PHP v3 prior to 3.288.1. The buildEndpoint method relies on the Guzzle Psr7 UriResolver utility, which strips dot segments from the request path in accordance with RFC 3986. Under certain conditions, this could lead to an arbitrary object being accessed.

Versions of the AWS SDK for PHP v3 before 3.288.1 are affected by this issue.

Patches

Upgrade to the AWS SDK for PHP >= 3.288.1, if you are on version < 3.288.1.

References

RFC 3986 - [https://datatracker.ietf.org/doc/html/rfc3986](https://datatracker.ietf.org/doc/html/rfc3986#section-5.2.4)

For more information

If you have any questions or comments about this advisory, please contact [AWS's Security team](mailto:aws-security@amazon.com).