How severe is CVE-2021-42103?

CVE-2021-42103 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-2021-42103 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42103?

CVE-2021-42103 primarily affects Trendmicro Apex One. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-42103?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-42103 published?

CVE-2021-42103 was published on 2021-10-21 and last updated on 2026-06-17.

CVE-2021-42103

CVE-2021-42103 is a high-severity vulnerability in Trendmicro Apex One with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-427.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 4.6
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-427
Affected product: Trendmicro Apex One
Published: 2021-10-21
Last modified: 2026-06-17

Description

An uncontrolled search path element vulnerabilities in Trend Micro Apex One and Apex One as a Service could allow a local attacker to escalate privileges on affected installations. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. This vulnerability is similar but not identical to CVE-2021-42101.

Frequently asked questions

What is CVE-2021-42103?: An uncontrolled search path element vulnerabilities in Trend Micro Apex One and Apex One as a Service could allow a local attacker to escalate privileges on affected installations. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. This vulnerability is similar but not identical to CVE-2021-42101.
How severe is CVE-2021-42103?: CVE-2021-42103 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-2021-42103 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42103?: CVE-2021-42103 primarily affects Trendmicro Apex One. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-42103?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-42103 published?: CVE-2021-42103 was published on 2021-10-21 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:*
cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:saas:*:*:*

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Other CWE-427 (Uncontrolled Search Path Element) vulnerabilities

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CVE-2019-25268 — Critical (CVSS 9.8): NREL BEopt 2.8.0.0 contains a DLL hijacking vulnerability that allows attackers to load arbitrary libraries by tricking…
CVE-2023-53959 — Critical (CVSS 9.8): FileZilla Client 3.63.1 contains a DLL hijacking vulnerability that allows attackers to execute malicious code by…
CVE-2025-65741 — Critical (CVSS 9.8): Sublime Text 3 Build 3208 or prior for MacOS is vulnerable to Dylib Injection. An attacker could compile a .dylib file…
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