CVE-2021-36741
Published: November 3, 2021
Official Description
Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security contain an improper input validation vulnerability that allows a remote attacker to upload files.
CISA KEV Advisory
Trend Micro Multiple Products Improper Input Validation Vulnerability
Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security contain an improper input validation vulnerability that allows a remote attacker to upload files.
Apply updates per vendor instructions.
Risk Analysis
This improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security allows a remote attacker to upload files. Its inclusion in CISA's KEV and active exploitation in the wild make it a critical vulnerability.
This vulnerability is actively being exploited in the wild, as confirmed by its presence in CISA's KEV. Exploitation can be performed remotely by submitting crafted input.
Apply the latest security updates for Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security. Implement robust input validation and file upload security measures.
Technical Analysis
CVE-2021-36741 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-2021-36741 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.
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-36741 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