An improper access control vulnerability in Trend Micro Apex One, Trend Micro Apex One as a Service and OfficeScan XG SP1 on a resource used by the service could allow 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.
Conclusion & alert: CVE-2021-25253 is rated Moderate Risk (52.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.09%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
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 | 2025-03-30 | 8.46% | 1.09% | -7.37% |
| 2 | 2025-03-29 | 1.09% | 8.46% | +7.37% |
| 3 | 2025-03-28 | — | 1.09% | — |
Full EPSS history (13 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | [email protected] |
| 7.2 | 2.0 | HIGH |
|
3.9 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| trendmicro | apex_one | 2019 | cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:* |
| trendmicro | apex_one | 2019 | cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:saas:*:*:* |
| trendmicro | officescan | xg | cpe:2.3:a:trendmicro:officescan:xg:sp1:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://success.trendmicro.com/solution/000286019 | Vendor Advisory |
| https://success.trendmicro.com/solution/000286157 | Vendor Advisory |
| https://www.zerodayinitiative.com/advisories/ZDI-21-401/ | Third Party Advisory VDB Entry |