Block 2 more gadget types (commons-dbcp2, CVE-2020-35490/CVE-2020-35491)

[cowtowncoder]

Another gadget type(s) reported regarding class(es) of org.apache.commons:commons-dbcp2. library.
See https://medium.com/@cowtowncoder/on-jackson-cves-dont-panic-here-is-what-you-need-to-know-54cd0d6e8062 for description of the general problem.

Reporter(s): Al1ex@knownsec
Mitre ids:
* CVE-2020-35490
* CVE-2020-35491

Fix is included in:

• 2.9.10.8 (usable via jackson-bom version 2.9.10.20210106)
• 2.6.7.5
• Not considered valid CVE for Jackson 2.10.0 and later (see https://medium.com/@cowtowncoder/jackson-2-10-safe-default-typing-2d018f0ce2ba)