CVE-2017-3207

The Java implementations of AMF3 deserializers in WebORB for Java by Midnight Coders, version 5.1.1.0, derive class instances from java.io.Externalizable rather than the AMF3 specifications recommendation of flash.utils.IExternalizable. A remote attacker with the ability to spoof or control an RMI server connection may be able to send serialized Java objects that execute arbitrary code when deserialized.

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• http://www.securityfocus.com/bid/97384
• http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-execution
• https://codewhitesec.blogspot.com/2017/04/amf.html
• https://www.kb.cert.org/vuls/id/307983
• http://www.securityfocus.com/bid/97384
• http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-execution
• https://codewhitesec.blogspot.com/2017/04/amf.html
• https://www.kb.cert.org/vuls/id/307983