CVE-2023-35311 — Microsoft Outlook Security Feature Bypass Vulnerability
Microsoft Outlook Security Feature Bypass Vulnerability
Published
2023-07-11T17:03:27.227Z
Last modified
2025-10-21T23:05:43.274Z
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
CISA KEV — Actively Exploited
01What is this vulnerability?
Microsoft Outlook Security Feature Bypass Vulnerability
02Affected products
| Vendor | Product | Versions |
|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 |
| Microsoft | Microsoft Office 2019 | 19.0.0 |
| Microsoft | Microsoft Outlook 2016 | 16.0.0.0 |
| Microsoft | Microsoft Outlook 2013 | 14.0.0 |
| Microsoft | Microsoft Outlook 2013 Service Pack 1 | 15.0.0.0 |
03Active exploitation status
Yes — actively exploited. Added to the CISA KEV catalog on 2023-07-11. Ransomware use: Unknown.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:
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07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2023-07-11T17:03:27.227Z
- Last modified: 2025-10-21T23:05:43.274Z
- Added to CISA KEV: 2023-07-11
- BOD 22-01 due: 2023-08-01
09References
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