CVE-2021-27059
Published: 11 March 2021
Summary
CVE-2021-27059 is a high-severity an unspecified weakness vulnerability in Microsoft Office. Its CVSS base score is 7.6 (High).
Operationally, ranked in the top 13.7% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).
Deeper analysis
CVE-2021-27059 is a remote code execution vulnerability affecting Microsoft Office. It carries a CVSS 3.1 base score of 7.6 with the vector AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H, indicating network-accessible exploitation that requires high attack complexity, high privileges, and user interaction while producing high impacts on confidentiality, integrity, and availability along with a scope change.
An attacker meeting the privilege and interaction prerequisites can leverage the flaw to execute arbitrary code on an affected system, potentially compromising the confidentiality, integrity, and availability of data across security boundaries.
Microsoft has published remediation guidance through its Security Response Center advisory, and the vulnerability appears in CISA's catalog of known exploited vulnerabilities, confirming real-world exploitation activity.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-13830
Vulnerability details
Microsoft Office Remote Code Execution Vulnerability
- CWE(s)
- KEV Date Added
- 03 November 2021
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely application of Microsoft patches that remediate CVE-2021-27059 before exploitation can succeed.
Enforces least-privilege execution so that even a successful Office RCE cannot obtain the high privileges required by the CVSS vector.
Restricts Office functionality (e.g., macros, embedded objects) that an attacker must abuse to trigger the RCE after user interaction.