CISA Warns DoD, Feds To Fix Critical Windows Vulnerability - Breaking Defense

Homeland Security’s Cybersecurity and Infrastructure Security Agency issued an emergency directive last night requiring the Pentagon and all other executive branch agencies to fix a Microsoft Windows vulnerability that could allow attackers to gain control of entire networks.

The vulnerability, formally called CVE-2021-34527 and dubbed PrintNightmare by security researchers, affects a Microsoft Windows service called print spooler. Print spooler enables printing capabilities on local networks. CISA’s emergency directive notes that PrintNightmare “poses an unacceptable risk… and requires emergency action” because it allows attackers to gain administrative control of IT systems and to remotely run malicious code.

Microsoft first disclosed PrintNightmare on July 1, less than a month after security researchers accidentally disclosed another bug in print spooler called CVE-2021-1675. The tech giant deemed PrintNightmare’s threat to confidentiality, integrity, and availability to be “high,” with an overall severity rating of eight out of 10 based on the industry-standard Common Vulnerability Scoring System.

Microsoft issued an out-of-band patch on July 6, but less than 13 hours after its release, a security researcher revealed the emergency patch was deficient. (Microsoft’s July 2021 cumulative updates are supposed to patch both print spooler vulnerabilities.)