RDCMan was always a standalone tool, not included with Windows OS versions, yet, it gained a lot of traction with system administrators in the late 2000s and early 2010s, when there weren't that many tools of its kind available online for free.
Microsoft kept the tool up to date across the years, even reaching v2.7 in 2014, the time of its last update.
However, RDCMan was never a fully-featured solution for remote management, and Microsoft rolled out alternative tools across the years.
This includes adding a built-in remote management tool (MSTSC) in the Windows OS itself and releasing an official Remote Desktop app on the Windows Store.
Microsoft said that both of the newer tools support more features, and receive security updates on a regular basis.
However, today, there are still a lot of users who are still using RDCMan, primarily because the app has better features for managing multiple connections at once, a feature that's often used in enterprise environments.
But this week, with the release of the March 2020 Patch, RDMan's official demise came to be. Microsoft said it received a report about a new bug in RDCMan that could allow an attacker to retrieve data from an RDCMan user's computer.
"To exploit the vulnerability, an attacker could create an RDG file containing specially crafted XML content and convince an authenticated user to open the file," Microsoft said in a security advisory for CVE-2020-0765.
Instead of fixing the bug, Microsoft decided to retire RDCMan, seeing no reason to revive an app that received its last update almost six years ago.
Users who continue using the app should be aware not to open any RDCMan connection configuration (RDG) files they receive unsolicited or from unknown sources.
Microsoft credited UK security researcher Ethan Sterling with finding and reporting the CVE-2020-0765 bug in RDCMan.
UPDATE on February 16, 2021: In a tweet, almost a year after RDCMan was discontinued, Mark Russinovich, co-creator of the SysInternals package, announced that RDCMan would be supported part of the SysInternals package going forward.
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