Integer overflow in Microsoft 365 Apps
CVE-2021-31178
Microsoft Office Information Disclosure Vulnerability
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.160 (96.9th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.160 · newest: 0.160 · change: 0.000
Affected products
- Microsoft 365 Apps
- Microsoft Excel — versions 2013, 2016
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Excel 2013 Service Pack 1 — versions 15.0.0.0
- Microsoft Excel 2016 — versions 16.0.0.0
- Microsoft Office 2013 Service Pack 1 — versions 15.0.0
- Microsoft Office 2016 — versions 16.0.0
- Microsoft Office 2019 — versions 19.0.0
- Microsoft Office Online Server — versions 16.0.1
- Microsoft Office Web Apps Server 2013 Service Pack 1 — versions 15.0.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31178 (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-31178?
- CVE-2021-31178 is a medium-severity vulnerability in Microsoft 365 Apps, classified under Integer Underflow. CVSS score: 5.5/10. Published 2021-05-11.
- How severe is CVE-2021-31178?
- Medium severity. CVSS v3 base score is 5.5 out of 10.
- Is CVE-2021-31178 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.