DNN (aka DotNetNuke) 9.2 through 9.2.2 uses a weak encryption algorithm to protect input parameters. NOTE: this issue exists because of an incomplete fix for CVE-2018-15811.
https://www.dnnsoftware.com/community/security/security-center
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-18325