There are one or two image manipulation operations performed within PKP software – e.g. creation of thumbnails of various sizes when cover images are uploaded to submissions. It’s very unlikely that these could be abused but I suppose it’s possible. I wouldn’t lose sleep over it, but updating the underlying tools on the server is the best way to mitigate any risk; these libraries aren’t bundled with OJS itself.
Regards,
Alec Smecher
Public Knowledge Project Team