Security News > 2021 > April > Microsoft partially fixes Windows 7, Server 2008 vulnerability

Microsoft has partially fixed a local privilege escalation vulnerability impacting all Windows 7 and Server 2008 R2 devices.

Security researcher Clément Labro discovered that insecure permissions on the registry keys of the RpcEptMapper and DnsCache services enable attackers to trick the RPC Endpoint Mapper service to load malicious DLLs on Windows 7 and Windows Server 2008R2.

While Microsoft addressed the issue for the RpcEptMapper registry key in the April 2021 Windows Updates release by changing permissions to no longer include 'Create Subkey' for groups Authenticated Users and Users, the company hasn't yet fixed the vulnerability for DnsCache.

An open-source exploit tool for this Windows 7 / 2008R2 RpcEptMapper registry key vulnerability is available since February.

This bug still affects Windows 7 and Server 2008 R2 devices, even if they are enrolled in Microsoft's Extended Security Updates program or not until Microsoft will release security updates for ESU customers to address the issue fully.

"At this point, if you are still using Windows 7 / Server 2008 R2 without isolating these machines properly in the network first, then preventing an attacker from getting SYSTEM privileges is probably the least of your worries," as Labro said.

News URL

https://www.bleepingcomputer.com/news/security/microsoft-partially-fixes-windows-7-server-2008-vulnerability/