Vulnerability in Microsoft 365 Apps
CVE-2023-35311
Microsoft Outlook Security Feature Bypass Vulnerability
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.155 (96.8th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.155 · newest: 0.155 · change: 0.000
Affected products
- Microsoft 365 Apps
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Office 2019 — versions 19.0.0
- Microsoft Office Ltsc 2021 — versions 16.0.1
- Microsoft Outlook 2013 — versions 14.0.0
- Microsoft Outlook 2013 Service Pack 1 — versions 15.0.0.0
- Microsoft Outlook 2016 — versions 16.0.0.0
- Microsoft Office — versions 2019
- Microsoft Office 2019
- Microsoft Office 2021
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
Public proof-of-concept exploits
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2023-35311 (vendor-advisory, Patch, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2023-35311?
- CVE-2023-35311 is a high-severity vulnerability in Microsoft 365 Apps, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 8.8/10. Published 2023-07-11.
- How severe is CVE-2023-35311?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2023-35311 known to be exploited?
- Yes. CVE-2023-35311 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-07-11), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.