CVE-2021-36742

Exp

A 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 local attacker to escalate privileges on affected installations. Please note: an attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

Published: 2021-07-29 Last update: 2025-10-31 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36742 is rated Critical Active Threat (83.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.43%). CISA KEV confirms active exploitation (added 2021-11-03) affecting Trend Micro / Apex One, Apex One as a Service, and Worry-Free Business Security. a weakness (CWE-20) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-36742

Name: Trend Micro Multiple Products Improper Input Validation Vulnerability · CISA KEV detail

Exploit added: 2021-11-03

Action due: 2021-11-17

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2021-36742

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-20 1.87% 1.43% -0.44%
2 2025-11-21 4.43% 1.87% -2.56%
3 2025-11-18 — 4.43% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36742

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
4.6 2.0 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 6.4 [email protected]

Weakness enumeration for CVE-2021-36742

Affected software / configurations for CVE-2021-36742

Vendor Product Version Raw CPE
trendmicro officescan xg cpe:2.3:a:trendmicro:officescan:xg:sp1:*:*:*:*:*:*
trendmicro officescan_business_security 10.0 cpe:2.3:a:trendmicro:officescan_business_security:10.0:sp1:*:*:*:*:*:*
trendmicro apex_one 2019 cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:*
trendmicro worry-free_business_security 10.0 cpe:2.3:a:trendmicro:worry-free_business_security:10.0:sp1:*:*:*:*:*:*

References for CVE-2021-36742

cvelogic Threat Intelligence