SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-35311

Microsoft Outlook Security Feature Bypass Vulnerability

KEVHIGH 8.8EPSS 15.5%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 1 August 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Microsoft Outlook Security Feature Bypass Vulnerability

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
15.52% probability · 97th percentile
CISA KEV
Listed 11 July 2023 · due 1 August 2023
Weakness
CWE-367
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 or discontinue use of the product if updates are unavailable. https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-35311; https://nvd.nist.gov/vuln/detail/CVE-2023-35311

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