Microsoft Issues Emergency Patch For PrintNightmare Flaw

Microsoft has issued a patch for a worrying “PrintNightmare” vulnerability, which can allow a hacker to remotely take over a Windows PC.

The critical flaw is found in the Windows Print Spooler service, and was discovered last week by researchers at China-based security specialist Sangfor, which accidentally published proof-of-concept (PoC) exploit code.

The flaw has been dubbed PrintNightmare, and Microsoft has issued out-of-band security updates to address the flaw.

Update immediately

The flaw has been rated as critical, as attackers can remotely execute code with system-level privileges on affected machines. Essentially, the hacker could take over, install programs, steal data, or create new accounts.

Indeed, so serious is the flaw that Microsoft has even issued a patch for Windows 7 users, despite the fact that that operating system officially went out of support last year.

The patch was issued on Tuesday and is available for download here.

The patch should be included automatically via the Windows Update.

“A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations,” said Redmond.

“An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges,” it added. “An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.”

Redmond said that it recommends that users install these updates immediately.