Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Application Security

Defcon Talk Prompts New Windows Print Spooler Flaw Warning

Microsoft’s problems with security defects in the Windows Print Spooler utility are getting worse by the week.

Microsoft’s problems with security defects in the Windows Print Spooler utility are getting worse by the week.

After spending the last two months pushing out multiple Print Spooler fixes (one as an emergency, out-of-band update), Redmond’s security response team late Thursday acknowledged a new, unpatched bug that exposes Windows users to privilege escalation attacks.

Microsoft’s advisory describes an entirely new vulnerability — CVE-2021-34481 — that could be chained with another bug to launch code execution attacks.  

There is no patch available and Microsoft says the only workaround is for Windows users to stop and disable the Print Spooler service.

From the advisory:

An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations. 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.

An attacker must have the ability to execute code on a victim system to exploit this vulnerability.

Microsoft said the vulnerability has already been publicly disclosed and credited Dragos security researcher Jacob Baines with the discovery.

Advertisement. Scroll to continue reading.

[ Related: Did Microsoft Botch PrintNightmare Patch? ]

Strangely, Baines said on Twitter that Microsoft’s advisory came out of the blue and was not part of a coordinated vulnerability disclosure process.   

Baines said he reported the issue to Microsoft on June 18 and said it was unrelated to the PrintNightmare Print Spooler vulnerabilities.

The Dragos researcher plans to discuss the issue at the upcoming Defcon conference, scheduled for early August in Las Vegas.  In a talk titled Bring Your Own Print Driver Vulnerability, Baines is scheduled to talk about how to introduce vulnerable Windows print drivers to a fully patched system. 

[ Related: Microsoft Ships Emergency PrintNightmare Patch ]

The Defcon talk abstract reads:

What can you do, as an attacker, when you find yourself as a low privileged Windows user with no path to SYSTEM? Install a vulnerable print driver! In this talk, you’ll learn how to introduce vulnerable print drivers to a fully patched system. Then, using three examples, you’ll learn how to use the vulnerable drivers to escalate to SYSTEM.

Microsoft said it is working on a patch but did not provide a timeline for release.

Related: Microsoft Ships Emergency PrintNightmare Patch

Related: Did Microsoft Botch PrintNightmare Patch?

Related: Microsoft Patches 3 Under-Attack Windows Zero-Days

Related: Patch Tuesday: Microsoft Warns of Under-Attack Windows Kernel

Written By

Ryan Naraine is Editor-at-Large at SecurityWeek and host of the popular Security Conversations podcast series. He is a security community engagement expert who has built programs at major global brands, including Intel Corp., Bishop Fox and GReAT. Ryan is a founding-director of the Security Tinkerers non-profit, an advisor to early-stage entrepreneurs, and a regular speaker at security conferences around the world.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Cybercrime

The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Identity & Access

Zero trust is not a replacement for identity and access management (IAM), but is the extension of IAM principles from people to everyone and...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

Cyberwarfare

WASHINGTON - Cyberattacks are the most serious threat facing the United States, even more so than terrorism, according to American defense experts. Almost half...