Take this with a grain of salt: They claim that the Struts vulnerability in question is specifically CVE-2017-9805, and cite a William Baird & Co. report [1]. However, the report in question says nothing about a specific CVE, only that it was "the Apache Struts flaw". Struts has had multiple vulnerabilities recently, such as one back in February (CVE-2017-5638). It's possible it was one of these that they failed to patch.
[1] https://baird.bluematrix.com/docs/pdf/dbf801ef-f20e-4d6f-91c...