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EXPOSURES › CVE-2021-42321

CVE-2021-42321

CRITICAL ⌖ ON CISA KEV · EXPLOITED
DETAIL
SourceCISA-KEV · kev Published2021-11-17 Referencehttps://nvd.nist.gov/vuln/detail/CVE-2021-42321 ↗
⚡ RCE ⌖ EXPLOITED IN THE WILD SHAME 72/100 ransomwarerceexploited-in-wildunpatched

Microsoft Exchange Server vulnerabilities allowed authenticated attackers to execute remote code, impacting DIB organizations using the platform.

CVE-2021-42321, alongside related vulnerabilities like ProxyLogon and ProxyNotShell, enabled remote code execution via improper input validation. DIB organizations relying on vulnerable Exchange Server instances face significant compliance risks (NIST 800-171 controls 3.a, 3.b, 3.c, 4.a) and potential data exposure; immediate patching and version upgrades are critical.

Shame score — Microsoft's history of critical Exchange Server RCE vulnerabilities demonstrates a pattern of systemic security failures and inadequate validation practices.

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

PLAYERS IMPLICATED
Microsoft · vendorExchange · product
DESCRIPTION

An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.

SENTIMENT · TRUSTED SOURCES
synthesis severe-fallout -0.60
Microsoft faced severe fallout for CVE-2021-42321, a critical RCE in Exchange Server that allowed authenticated attackers to execute remote code. The vulnerability was widely reported as a major secur
cooey ↗ severe-fallout -0.80
NVD entry confirms critical RCE in Exchange, reflecting severe industry impact and Microsoft's failure to prevent a high-severity exploit.
"An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution."
xposedornot.com ↗ severe-fallout +0.00
XposedOrNot is a breach directory with no specific commentary on CVE-2021-42321 or Microsoft's handling.
CISA ↗ severe-fallout +0.00
CISA ICS Advisories page is a generic advisory portal with no specific commentary on CVE-2021-42321 or Microsoft's handling.
www.govexec.com ↗ severe-fallout +0.00
Government Executive article is unrelated to CVE-2021-42321 or Microsoft's handling.
NIST ↗ severe-fallout +0.00
NIST NVD page is a generic database portal with no specific commentary on CVE-2021-42321 or Microsoft's handling.
app.opencve.io ↗ severe-fallout +0.00
OpenCVE page is a generic vulnerability listing tool with no specific commentary on CVE-2021-42321 or Microsoft's handling.
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