[Security] Use yaml.SafeLoader instead of yaml.Loader/yaml.FullLoader (same as yaml.UnsafeLoader)

[kamadorueda]

here: https://github.com/awslabs/aws-cfn-template-flip/blob/master/cfn_tools/yaml_loader.py#L20

as explained here:

https://pyyaml.org/wiki/PyYAMLDocumentation#LoadingYAML

an in the source-code comment:

is insecure, we should use SafeLoader instead

[koiker]

I have updated the Loader to FullLoader in the fix/max-col-width. Are you using Python 2.7 or 3.x?
The new version will deprecate python 2.7 and will only work with python 3.x

[kamadorueda]

That's awesome!

[kamadorueda]

Seems like FullLoader is also vulnerable: yaml/pyyaml#420

I've updated the issue

[koiker]

Fixed in #102