How severe is CVE-2020-24557?

CVE-2020-24557 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-24557 being actively exploited?

Yes. CVE-2020-24557 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2020-24557?

CVE-2020-24557 primarily affects Trendmicro Apex One. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-24557?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2020-24557 have an EU (EUVD) identifier?

Yes. CVE-2020-24557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-17276. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2020-24557 published?

CVE-2020-24557 was published on 2020-09-01 and last updated on 2026-06-17.

CVE-2020-24557

CVE-2020-24557 is a high-severity vulnerability in Trendmicro Apex One with a CVSS 3.x base score of 7.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03).

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2020-17276
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Affected product: Trendmicro Apex One
Published: 2020-09-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-24557?: 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.
How severe is CVE-2020-24557?: CVE-2020-24557 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-24557 being actively exploited?: Yes. CVE-2020-24557 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2020-24557?: CVE-2020-24557 primarily affects Trendmicro Apex One. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-24557?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2020-24557 have an EU (EUVD) identifier?: Yes. CVE-2020-24557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-17276. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2020-24557 published?: CVE-2020-24557 was published on 2020-09-01 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:trendmicro:apex_one:-:*:*:*:saas:*:*:*
cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:*
cpe:2.3:a:trendmicro:worry-free_business_security:10.0:sp1:*:*:*:*:*:*

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