CVE-2021-40539
Published 2021-09-07 · Updated 2026-06-17 · Source cve@mitre.org
Summary
CVE-2021-40539 is a critical-severity (CVSS 9.8) vulnerability in Zoho ManageEngine. CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by November 17, 2021. CISA also lists it as known to be used in ransomware campaigns, so it should be prioritised accordingly. Zoho has 9 vulnerabilities in the KEV catalog, 2 of them linked to ransomware.
All 9 known-exploited Zoho vulnerabilities →Description
Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Zoho — ManageEngine
Name: Zoho ManageEngine ADSelfService Plus Authentication Bypass Vulnerability
Date added: 2021-11-03 · Due: 2021-11-17
Required action: Apply updates per vendor instructions.
References
- http://packetstormsecurity.com/files/165085/ManageEngine-ADSelfService-Plus-Authentication-Bypass-Code-Execution.html
- https://www.manageengine.com
- https://www.manageengine.com/products/self-service-password/kb/how-to-fix-authentication-bypass-vulnerability-in-REST-API.html
- http://packetstormsecurity.com/files/165085/ManageEngine-ADSelfService-Plus-Authentication-Bypass-Code-Execution.html
- https://www.manageengine.com
- https://www.manageengine.com/products/self-service-password/kb/how-to-fix-authentication-bypass-vulnerability-in-REST-API.html
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40539