CVE-2020-24557
HighExploitedPublic exploitA 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.
Published Sep 1, 2020 · Updated Oct 31, 2025
Key Facts
Patch immediately- CVE-2020-24557 is a high-severity vulnerability (CVSS 7.8 v3.1) affecting Apex One (Trendmicro), Worry-Free Business Security (Trendmicro), Trend Micro Apex One and 1 more product.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 21, 2021. Public exploit code is available.
- EPSS estimates a 2.7% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
2.7%
Higher than 85.4% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| Industry KEV feed | Apr 21, 2021 | May 3, 2022 | Not reported |
| CIRCL KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
5 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Apex OneTrendmicro | 2019 | n/a |
| Worry-Free Business SecurityTrendmicro | 10.0-sp1 | n/a |
| Trend Micro Apex One | >= 2009 (on premise), SaaS | n/a |
| Trend Micro Worry-Free Business Security | >= 10.0 SP1 | n/a |
Timeline
Publicly disclosed
Sep 1, 2020
Added to Industry KEV feed
Apr 21, 2021
Added to CISA KEV
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Last updated
Oct 31, 2025
References
- advisoryhttps://success.trendmicro.com/solution/000263632
- advisoryhttps://success.trendmicro.com/solution/000267260
- advisoryhttps://www.zerodayinitiative.com/advisories/ZDI-20-1094/
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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.
Affected: Apex One (Trendmicro) versions 2019; Worry-Free Business Security (Trendmicro) versions 10.0-sp1; Trend Micro Apex One versions >= 2009 (on premise), SaaS, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 21, 2021.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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