Microsoft’s legacy Support Diagnostic Tool, designed to let support agents remotely analyze Windows problems, contained multiple exploitable weaknesses. The DogWalk vulnerability was first reported by Mitja Kolsek in January 2020; it involved path traversal in the sdiageng.dll library and malicious .diagcab files. Microsoft initially did not treat the issue as a security vulnerability, but released a patch in August 2022 after exploitation in the wild was reported.
A separate MSDT flaw, later named Follina, was publicly disclosed by Nao Sec on May 27, 2022. A malicious Microsoft Office document could use remote templates to invoke MSDT and execute PowerShell code without explicit user notification. Microsoft assigned CVE-2022-30190 on May 30, advised users to disable MSDT through the Windows registry, and patched the flaw in June 2022. Attacks had been observed against computers in Russia and Belarus since April, while suspected Chinese state actors were believed to have targeted the Tibetan government in exile; those actor attributions remain qualified. Microsoft announced that legacy inbox troubleshooters would be deprecated after May 23, 2023, with MSDT scheduled for removal in 2025 and replacement by Get Help.