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PatchSiren cyber security CVE debrief

CVE-2021-36741 Trend Micro CVE debrief

CVE-2021-36741 is a Trend Micro improper input validation vulnerability affecting Apex One, Apex One as a Service, and Worry-Free Business Security. CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03, making it a high-priority remediation item for defenders. The supplied corpus does not include a CVSS score, so prioritization should be driven by KEV status and vendor remediation guidance.

Vendor
Trend Micro
Product
Apex One, Apex One as a Service, and Worry-Free Business Security
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Administrators and security teams responsible for Trend Micro Apex One, Apex One as a Service, or Worry-Free Business Security deployments; vulnerability management teams tracking CISA KEV items; and incident responders validating exposure and remediation status.

Technical summary

The available source data identifies the issue as an improper input validation vulnerability in Trend Micro multiple products. The official KEV entry ties the CVE to Apex One, Apex One as a Service, and Worry-Free Business Security and directs organizations to apply updates per vendor instructions. The supplied corpus does not provide further exploitation mechanics, impact details, or a CVSS rating.

Defensive priority

High. This CVE is listed in CISA KEV, with a remediation due date of 2021-11-17, so exposed instances should be treated as urgent patch-management items.

Recommended defensive actions

  • Identify all Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security installations in your environment.
  • Apply the vendor updates referenced in the CISA KEV entry and Trend Micro solution guidance as soon as possible.
  • Confirm remediation across all affected hosts, including centrally managed and remote deployments.
  • Validate that vulnerable versions are no longer present after patching and document closure for vulnerability management tracking.
  • Monitor vendor advisories and internal alerts for any follow-up guidance related to this CVE.

Evidence notes

CISA’s Known Exploited Vulnerabilities feed lists this CVE on 2021-11-03 with the required action “Apply updates per vendor instructions” and a due date of 2021-11-17. The supplied metadata also cites Trend Micro solution references 000287819 and 000287820 and links the issue to the official CVE record and NVD detail page. No CVSS score was included in the provided corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-36741 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-36741

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2021-36741 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-36741

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.