There are a few RCE disclosures for Valve games related to this previously
- https://hackerone.com/reports/542180
- https://nvd.nist.gov/vuln/detail/CVE-2020-9005
- https://nvd.nist.gov/vuln/detail/CVE-2020-7952
- https://nvd.nist.gov/vuln/detail/CVE-2020-7951