This code too could be more paranoid: the fallbacks are 'PUBLIC', so subverting the parsing logic may bypass the blacklist. Under the hood, the iptype() function converts the IP address to a list of bits using strBin() and then tries to match this list against the previously shown IP ranges:
Jenkins versions 2.56 and earlier as well as 2.46.1 LTS and earlier are vulnerable to an unauthenticated remote code execution. An unauthenticated remote code execution vulnerability allowed attackers to transfer a serialized Java `SignedObject` object to the Jenkins CLI, that would be deserialized using a new `ObjectInputStream`, bypassing the existing blacklist-based protection mechanism. We're fixing this issue by adding `SignedObject` to the blacklist. We're also backporting the new HTTP CLI protocol from Jenkins 2.54 to LTS 2.46.2, and deprecating the remoting-based (i.e. Java serialization) CLI protocol, disabling it by default.
SSRF Blacklist bypass using DNS Rebinding for Java Servers
Spring Framework 3.0.0 through 3.0.5, Spring Security 3.0.0 through 3.0.5 and 2.0.0 through 2.0.6, and possibly other versions deserialize objects from untrusted sources, which allows remote attackers to bypass intended security restrictions and execute untrusted code by (1) serializing a java.lang.Proxy instance and using InvocationHandler, or (2) accessing internal AOP interfaces, as demonstrated using deserialization of a DefaultListableBeanFactory instance to execute arbitrary commands via the java.lang.Runtime class. 2ff7e9595c
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