CVE-2018-14720 (published 2019-01-02T18:29Z)

FasterXML jackson-databind 2.x before 2.9.7 might allow attackers to conduct external XML entity (XXE) attacks by leveraging failure to block unspecified JDK classes from polymorphic deserialization.

Severity: HIGH
CVSS v2 base score: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.8, CRITICAL (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-611
cwe_name: Improper Restriction of XML External Entity Reference
description: The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
extended_description: 
            XML documents optionally contain a Document Type Definition (DTD), which, among other features, enables the definition of XML entities. It is possible to define an entity by providing a substitution string in the form of a URI. The XML parser can access the contents of this URI and embed these contents back into the XML document for further processing.
            By submitting an XML file that defines an external entity with a file:// URI, an attacker can cause the processing application to read the contents of a local file. For example, a URI such as "file:///c:/winnt/win.ini" designates (in Windows) the file C:\Winnt\win.ini, or file:///etc/passwd designates the password file in Unix-based systems. Using URIs with other schemes such as http://, the attacker can force the application to make outgoing requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions or hide the source of attacks such as port scanning.
            Once the content of the URI is read, it is fed back into the application that is processing the XML. This application may echo back the data (e.g. in an error message), thereby exposing the file contents.
         
         
cwe_id: CWE-502
cwe_name: Deserialization of Untrusted Data
description: The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
extended_description: 
            It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security -- which is a dangerous security assumption.
            Data that is untrusted can not be trusted to be well-formed.
            When developers place no restrictions on "gadget chains," or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.
         
         

Fix information:
repo_url: https://github.com/FasterXML/jackson-databind
commit_details: repo_url: https://github.com/FasterXML/jackson-databind
author: Tatu Saloranta
author_date: 2018-08-16 14:42:57-07:00
msg: Fix #2097 for 2.6.7.2
repository: repo_url: https://github.com/FasterXML/jackson-databind
repo_name: FasterXML/jackson-databind
description: General data-binding package for Jackson (2.x): works on streaming API (core) implementation(s)
repo_language: Java
owner: FasterXML
file_changes: filename: VERSION
change_type: ModificationType.MODIFY
diff: @@ -5,7 +5,10 @@ Project: jackson-databind
 ------------------------------------------------------------------------
 
 2.6.7.2 (not yet released)
+
 #1737: Block more JDK types from polymorphic deserialization
+#2097: Block more classes from polymorphic deserialization (CVE-2018-14718
+  - CVE-2018-14721)
 
 2.6.7.1 (11-Jul-2017)
 

programming_language: Markdown
filename: BeanDeserializerFactory.java
change_type: ModificationType.MODIFY
diff: @@ -68,6 +68,12 @@ public class BeanDeserializerFactory
         s.add("com.mchange.v2.c3p0.JndiRefForwardingDataSource");
         s.add("com.mchange.v2.c3p0.WrapperConnectionPoolDataSource");
 
+        // [databind#2097]: some 3rd party, one JDK-bundled
+        s.add("org.slf4j.ext.EventData");
+        s.add("flex.messaging.util.concurrent.AsynchBeansWorkManagerExecutor");
+        s.add("com.sun.deploy.security.ruleset.DRSHelper");
+        s.add("org.apache.axis2.jaxws.spi.handler.HandlerResolverImpl");
+
         DEFAULT_NO_DESER_CLASS_NAMES = Collections.unmodifiableSet(s);
     }
 

programming_language: Java