SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-23397

Microsoft Office Outlook Privilege Escalation Vulnerability

KEVCRITICAL 9.8EPSS 97.4%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 4 April 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Microsoft Outlook Elevation of Privilege Vulnerability

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
97.41% probability · 100th percentile
CISA KEV
Listed 14 March 2023 · due 4 April 2023
Weakness
CWE-20, CWE-294
Affected
microsoft/365 apps · microsoft/office · microsoft/office long term servicing channel · microsoft/outlook
Source
secure@microsoft.com

CISA notes

Apply updates per vendor instructions. https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-23397, https://msrc.microsoft.com/blog/2023/03/microsoft-mitigates-outlook-elevation-of-privilege-vulnerability/, ; https://nvd.nist.gov/vuln/detail/CVE-2023-23397

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.