CVE-2021-27059
Published: November 3, 2021
Official Description
Microsoft Office contains an unspecified vulnerability that allows for remote code execution.
CISA KEV Advisory
Microsoft Office Remote Code Execution Vulnerability
Microsoft Office contains an unspecified vulnerability that allows for remote code execution.
Apply updates per vendor instructions.
Risk Analysis
This unspecified vulnerability in Microsoft Office allows for remote code execution. Although a CVSS score is not available, its HIGH severity and confirmed exploitation in the wild by CISA indicate it is a critical threat. The low EPSS score of 0.02045 is superseded by the confirmed active exploitation.
This vulnerability is actively being exploited in the wild, as confirmed by its inclusion in CISA's KEV catalog. The nature of remote code execution implies it is remotely exploitable.
Organizations should apply the latest security updates for Microsoft Office to mitigate this vulnerability. Users should also exercise caution with untrusted documents and emails.
Technical Analysis
CVE-2021-27059 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-27059 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-27059 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1