Zoho has shipped an urgent patch for an authentication bypass vulnerability in its ManageEngine ADSelfService Plus alongside a warning that the bug is already exploited in attacks.
Tracked as CVE-2021-40539, the security flaw is deemed critical as it could be exploited to take over a vulnerable system.
The issue, according to a Zoho advisory, affects the REST API URLs in ADSelfService Plus and could be abused to achieve remote code execution. Technical details on the vulnerability have yet to be published.
“This is a critical issue. We are noticing indications of this vulnerability being exploited,” Zoho warned.
All ADSelfService Plus builds up to 6113 were found vulnerable to the issue and customers are advised to immediately update ADSelfService Plus to build 6114 or later.
In a separate advisory on Tuesday, the U.S. government’s Cybersecurity and Infrastructure Security Agency (CISA) urged administrators to review Zoho’s advisory and update ADSelfService Plus immediately.
“CVE-2021-40539 has been detected in exploits in the wild. A remote attacker could exploit this vulnerability to take control of an affected system,” CISA said.
An integrated self-service password management and single sign-on solution, ManageEngine ADSelfService Plus can be used with Active Directory and cloud apps to create password policies, implement authentication techniques, and enforce two-factor authentication (2FA), among others.