Use After Free in Microsoft 365 Apps
CVE-2021-31177
Microsoft Office Remote Code Execution Vulnerability
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.031 (87.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.031 · 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 2019 — versions 19.0.0
- Microsoft Office 2019 For Mac — versions 16.0.0
- Microsoft Office Online Server — versions 16.0.1
- Microsoft Office Web Apps Server 2013 Service Pack 1 — versions 15.0.1
- Microsoft Office — versions 2013, 2016, 2019
Weakness classification (CWE)
References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31177 (Patch, Vendor Advisory)
- www.zerodayinitiative.com/advisories/ZDI-21-576/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2021-31177?
- CVE-2021-31177 is a high-severity vulnerability in Microsoft 365 Apps, classified under Use After Free. CVSS score: 7.8/10. Published 2021-05-11.
- How severe is CVE-2021-31177?
- High severity. CVSS v3 base score is 7.8 out of 10.