A flaw was found in RESTEasy's IIOImageProvider, which decodes attacker-supplied image request bodies without enforcing any limit on the declared image dimensions or pixel count. A remote, unauthenticated attacker can send a small crafted image declaring enormous dimensions to trigger a very large memory allocation, exhausting the JVM heap and resulting in a denial of service.
Credits
Red Hat would like to thank Yu Bao (PayPal Cyber Security Team) for reporting this issue.