Logback deserialization whitelist bypass for Proxy objects

Deserialization of untrusted data vulnerability in QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules) allows Object Injection, albeit heavily restricted.

More precisely, an attacker able to influence serialized data sent to

SimpleSocketServer or SimpleSSLSocketServer can instantiate Proxy objects.

Although deserialization is heavily restricted by HardenedObjectInputStream and no

practical way to achieve remote code execution or significant privilege

escalation has been identified, this issue constitutes a bypass of the

intended security restrictions.

This issue affects logback: through 1.5.33 inclusive.