Security News > 2021 > August > Microsoft Warns of Another Unpatched Windows Print Spooler RCE Vulnerability

A day after releasing Patch Tuesday updates, Microsoft acknowledged yet another remote code execution vulnerability in the Windows Print Spooler component, adding that it's working to remediate the issue in an upcoming security update.
"A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations," the company said in its out-of-band bulletin, echoing the vulnerability details for CVE-2021-34481.
"An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights."
It's worth noting that the Windows maker has since released updates to change the default Point and Print default behavior, effectively barring non-administrator users from installing or updating new and existing printer drivers using drivers from a remote computer or server without first elevating themselves to an administrator.
As workarounds, Microsoft is recommending users to stop and disable the Print Spooler service to prevent malicious actors from exploiting the vulnerability.
The CERT Coordination Center, in a vulnerability note, is also advising users to block outbound SMB traffic to prevent connecting to a malicious shared printer.
News URL
Related news
- Microsoft Patches 125 Flaws Including Actively Exploited Windows CLFS Vulnerability (source)
- Microsoft: Windows CLFS Vulnerability Could Lead to ‘Widespread Deployment and Detonation of Ransomware’ (source)
- Microsoft lifts Windows 11 update block for some AutoCAD users (source)
- Critical PHP RCE vulnerability mass exploited in new attacks (source)
- Microsoft replacing Remote Desktop app with Windows App in May (source)
- Microsoft: Recent Windows updates make USB printers print random text (source)
- Microsoft patches Windows Kernel zero-day exploited since 2023 (source)
- Microsoft: March Windows updates mistakenly uninstall Copilot (source)
- Microsoft fixes Windows update bug that uninstalled Copilot (source)
- Critical Veeam Backup & Replication RCE vulnerability fixed, patch ASAP! (CVE-2025-23120) (source)
Related Vulnerability
DATE | CVE | VULNERABILITY TITLE | RISK |
---|---|---|---|
2021-07-16 | CVE-2021-34481 | Improper Privilege Management vulnerability in Microsoft products <p>A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations. | 0.0 |