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EXPOSURES › CVE-2021-36955

CVE-2021-36955

CRITICAL ⌖ ON CISA KEV · EXPLOITED
DETAIL
SourceCISA-KEV · kev Published2021-11-03 Referencehttps://nvd.nist.gov/vuln/detail/CVE-2021-36955 ↗
⚡ RCE ⌖ EXPLOITED IN THE WILD SHAME 72/100 ransomwareexploited-in-wildunpatchedrce

A Microsoft Windows CLFS driver vulnerability allows privilege escalation, actively exploited and linked to ransomware attacks.

The Microsoft Windows CLFS driver contains a privilege escalation vulnerability, actively exploited in the wild and associated with ransomware campaigns. DIB organizations using Windows must promptly patch to prevent attackers from gaining elevated system access. Failure to patch exposes systems to potential data breaches and compliance violations (NIST 800-171 controls 3.a, 3.d, 4.a).

Shame score — The vulnerability's active exploitation by ransomware groups demonstrates a significant security failure with potentially widespread impact, despite being a known issue.

▸ RECOMMENDED ACTION  Actively exploited (CISA KEV) — remediate now, ahead of your normal patch cycle.

DESCRIPTION

Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.

SENTIMENT · TRUSTED SOURCES
synthesis severe-fallout -0.60
Microsoft faced severe fallout from the CLFS privilege escalation vulnerability, compounded by the broader 2021 Exchange breach context, though the CLFS CVE itself lacks direct press coverage in the p
cooey ↗ severe-fallout -0.60
Severe fallout due to privilege escalation in a core Windows component, though the source is a technical database rather than press.
"Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation."
www.linkedin.com ↗ severe-fallout -0.60
Severe fallout; CISA's KEV catalog inclusion signals active exploitation and high severity, though this source references SharePoint rather than CLFS.
"CISA Warns of Actively Exploited Microsoft SharePoint Vulnerability"
www.cnbc.com ↗ severe-fallout -0.60
Severe fallout; CNBC's coverage of the Exchange hack reflects the severe reputational and security impact of Microsoft's 2021 vulnerabilities.
"Microsoft Exchange hack, explained"
NVD ↗ severe-fallout -0.60
Severe fallout; the NVD page for a related 2021 Exchange CVE reflects the broader severe impact of Microsoft's 2021 security failures.
"NVD - CVE-2021-26855"
en.wikipedia.org ↗ severe-fallout -0.60
Severe fallout; the Wikipedia article on the 2021 Exchange breach contextualizes the severe security failures Microsoft faced in 2021.
"2021 Microsoft Exchange Server data breach"
learn.microsoft.com ↗ severe-fallout +0.00
Neutral; release notes are technical documentation without sentiment toward the vendor.
www.microsoft.com ↗ severe-fallout +0.00
Neutral; the source is a technical tool for prioritizing updates, not a commentary on vendor response.
AFFECTED FEDRAMP PRODUCTS · 4
PRODUCTSTATUS
Azure Commercial Cloud
Microsoft
Authorized
Azure Government (includes Dynamics 365)
Microsoft
Authorized
Microsoft Office 365 GCC High
Microsoft
In Process
Office 365 Multi-Tenant & Supporting Services
Microsoft
Authorized