How severe is CVE-2021-36741?

CVE-2021-36741 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-36741 being actively exploited?

Yes. CVE-2021-36741 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-2021-36741?

CVE-2021-36741 primarily affects Trendmicro Officescan. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36741?

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-2021-36741 have an EU (EUVD) identifier?

Yes. CVE-2021-36741 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-23331. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2021-36741 published?

CVE-2021-36741 was published on 2021-07-29 and last updated on 2026-06-17.

CVE-2021-36741

CVE-2021-36741 is a high-severity vulnerability in Trendmicro Officescan with a CVSS 3.x base score of 8.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03). The underlying weakness is classified as CWE-434.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2021-23331
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-434
Affected product: Trendmicro Officescan
Published: 2021-07-29
Last modified: 2026-06-17

Description

An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.

Frequently asked questions

What is CVE-2021-36741?: An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.
How severe is CVE-2021-36741?: CVE-2021-36741 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-36741 being actively exploited?: Yes. CVE-2021-36741 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-2021-36741?: CVE-2021-36741 primarily affects Trendmicro Officescan. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36741?: 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-2021-36741 have an EU (EUVD) identifier?: Yes. CVE-2021-36741 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-23331. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2021-36741 published?: CVE-2021-36741 was published on 2021-07-29 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:trendmicro:officescan:xg:sp1:*:*:*:*:*:*
cpe:2.3:a:trendmicro:officescan_business_security:10.0:sp1:*:*:*:*:*:*
cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:*
cpe:2.3:a:trendmicro:worry-free_business_security:10.0:sp1:*:*:*:*:*:*

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