CVE-2020-24557: Trend Micro Multiple Products Improper Access Control Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 428 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 2.7%
EPSS score, percentile 85.7 of all scored records
- How severe?
- 7.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline . Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 2009 (on premise), SaaS
- 10.0 SP1
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: .
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 2009 (on premise), SaaS |
| Status | Versions |
|---|---|
| Affected | 10.0 SP1 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Trend Micro Apex One, OfficeScan, and Worry-Free Business Security on Microsoft Windows contain an improper access control vulnerability that may allow an attacker to manipulate a particular product folder to disable the security temporarily, abuse a specific Windows function, and attain privilege escalation.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2020-24557 to its Known Exploited Vulnerabilities (KEV) catalog on 3 Nov 2021.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 3 May 2022.
- The CVE record was published on 1 Sep 2020, 428 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 7.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 2.7% (percentile 85.7), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
A vulnerability in Trend Micro Apex One and Worry-Free Business Security 10.0 SP1 on Microsoft Windows may allow an attacker to manipulate a particular product folder to disable the security temporarily, abuse a specific Windows function and attain privilege escalation. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. Please note that version 1909 (OS Build 18363.719) of Microsoft Windows 10 mitigates hard links, but previous versions are affected.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
More exploited Trend Micro vulnerabilities
- CVE-2026-34926: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
- CVE-2025-54948: Trend Micro Apex One OS Command Injection Vulnerability
- CVE-2023-41179: Trend Micro Apex One and Worry-Free Business Security Remote Code Execution Vulnerability
- CVE-2022-40139: Trend Micro Apex One and Apex One as a Service Improper Validation Vulnerability
- CVE-2022-26871: Trend Micro Apex Central Arbitrary File Upload Vulnerability
- CVE-2019-18187: Trend Micro OfficeScan Directory Traversal Vulnerability