Redocly CLI: Path traversal when using `split` command

Impact

An OpenAPI or AsyncAPI description could make the split command write
files outside the chosen output directory, on the machine of anyone who runs
split against it. The write is constrained rather than a free file-write
primitive: component data is emitted only as YAML/JSON, and code-sample files are
named after the HTTP method, so an attacker can place or overwrite files at an
unintended path but has limited control over their name and contents.

Patches

Fixed in @redocly/cli v2.33.2.

Workarounds

Do not run the split command on API descriptions from untrusted or unreviewed sources.

To detect an exploit attempt, inspect the description's component names and
x-codeSamples lang values for a literal ../ — neither legitimately contains
path segments.