Oracle WebLogic has recently disclosed and patched remote-code-execution (RCE) vulnerabilities in its software, many of which were due to insecure deserialization. Oracle addressed the most recent vulnerability, CVE-2019-2729, in an out-of-band security patch on June 18, 2019. CVE-2019-2729 was assigned a CVSS score of 9.8, making it a critical vulnerability. This vulnerability is relatively easy to exploit, but requires Java Development Kit (JDK) 1.6. By default, WebLogic version 10.3.6 is shipped with JDK 1.6.

CVE-2019-2729 is essentially a bypass to CVE-2019-2725. This security issue, however, first surfaced in April 24 2017 as CVE-2017-3506.  We took a closer look at CVE-2019-2729 to see how this class of vulnerability has been remediated  — particularly via blacklisting or whitelisting — and why it has become a recurring security issue.