The XML parsers within multiple WSO2 products accept user-supplied XML data without properly configuring to prevent the resolution of external entities. This omission allows malicious actors to craft XML payloads that exploit the parser's behavior, leading to the inclusion of external resources. By leveraging this vulnerability, an attacker can read confidential files from the file system and access limited HTTP resources reachable by the product.

Additionally, the vulnerability can be exploited to perform denial of service attacks by exhausting server resources through recursive entity expansion or fetching large external resources.