CVE-2021-28478: microsoft microsoft sharepoint enterprise server 2016 Authentication Bypass by Spoofing
CVSS: 7.6v3.1HighModified
Published 11-05-2021Last modified 28-02-2025
Vulnerability summary
CVE-2021-28478 is a high (CVSS 7.6) Authentication Bypass by Spoofing vulnerability in microsoft microsoft sharepoint enterprise server 2016. EPSS estimates a 1.57% chance of exploitation in the next 30 days, higher than 75% of scored vulnerabilities.
CVSS score
7.6/10
010
High · v3.1 (CVE.org)EPSS score
1.57%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 11-05-2021PublishedVulnerability first disclosed.
- 28-02-2025Last modifiedVulnerability information updated.
Description
Microsoft SharePoint Server Spoofing Vulnerability
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 7.6Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST7.6HighCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Medium 5.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.57%
Chance of exploitation in the next 30 days
Percentile
75%
Versus all other CVEs
30-day change
0.00 pp
From 1.57% on 20-09-2026
20-09-202620-10-2026
EPSS score1.57%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Microsoft5 products
- microsoft sharepoint enterprise server 2016≥ 16.0.0, < 16.0.5161.1000
- microsoft sharepoint foundation 2013 service pack 1≥ 15.0.0, < 15.0.5345.1000
- microsoft sharepoint server 2019≥ 16.0.0, < 16.0.10374.20000
- sharepoint_foundation2013:sp1
- sharepoint_server2016 | 2019
1 vendor · 5 products
References
1 links
portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28478X Refsource MISCPatchVendor Advisory