synced 12 MIN AGO
01 Record

CVE-2021-43255

Microsoft Office Trust Center Spoofing Vulnerability

MediumPUBLISHEDCNA: microsoft
CNA base score5.5 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

02 Description

Microsoft Office Trust Center Spoofing Vulnerability

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
2.08% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 81.2% of scored records. A rank, not a probability.
NVD base score
5.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-12-15 14:15Z4 YR AGO
Last updated
2024-08-04 03:55Z2 YR AGO
Reserved
2021-11-02
Assigning CNA
microsoft
Record state
PUBLISHED
Severity
Medium (CVSS 5.5)
CNA CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
Weaknesses
No CWE assigned
Data version
5.1
Document digest
42857b79cfa0cfe22fa7dc23dd962d6c1ff8ed01b911b4c4e0a9146386ab655c

05 Affected products

VendorProductVersionsPlatforms
MicrosoftMicrosoft Office LTSC 202116.0.1 to < https://aka.ms/OfficeSecurityReleasesx64-based Systems, 32-bit Systems
MicrosoftMicrosoft Office 201919.0.0 to < https://aka.ms/OfficeSecurityReleases32-bit Systems, x64-based Systems
MicrosoftMicrosoft 365 Apps for Enterprise16.0.1 to < https://aka.ms/OfficeSecurityReleases32-bit Systems, x64-based Systems
MicrosoftMicrosoft Office 201616.0.0 to < 16.0.5254.100132-bit Systems, x64-based Systems
MicrosoftMicrosoft Office 2013 Service Pack 115.0.0 to < 15.0.5407.1000ARM64-based Systems, 32-bit Systems, x64-based Systems

06 References