CVE-2021-36741
An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security…
- 8.8HighCVSS base score
- 5.0%Exploitation in 30 daysEPSS · top 7.7% of all CVEs
- YesKnown exploitedin CISA's KEV since 3 Nov 2021
- YesPublic exploitsa reference or SSVC says so
Description
An 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 remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Trend Micro Multiple Products Improper Input Validation Vulnerability.
- Added
- 3 Nov 2021
- Fix due (US federal)
- 17 Nov 2021
- Used by ransomware
- Not known
Apply updates per vendor instructions.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 3 Nov 2021.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.
Timeline
ID reserved
By trendmicro
- 15 days later
· 15 days later
Published
- 3 months later
· 3 months later
Added to CISA KEV
Known exploited in the wild
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 5.0% · top 7.7% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Affected products
Trend Micro · Trend Micro Apex One
- affected 2019, SaaS
Trend Micro · Trend Micro OfficeScan
- affected XG SP1
Trend Micro · Trend Micro Worry-Free Business Security
- affected 10.0 SP1
References
References5
- https://success.trendmicro.com/solution/000287819 (opens in a new tab)x_refsource_MISCx_transferred
- https://success.trendmicro.com/solution/000287820 (opens in a new tab)x_refsource_MISCx_transferred
- https://success.trendmicro.com/jp/solution/000287796 (opens in a new tab)x_refsource_MISCx_transferred
- https://success.trendmicro.com/jp/solution/000287815 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36741 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-23331 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-36741)Record last updated .