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Zoho Patches Critical Zero-day Flaw in its ADSelfService plus Exploited in The Wild

Zoho Patches Critical Zero-day Flaw in its ADSelfService plus Exploited in The Wild

Zoho Patches Critical Zero-day Flaw in ADSelfService to patch a remote code execution (RCE) vulnerability existing in Zoho ADSelfService plus. The vulnerability allows the execution of unauthenticated remote arbitrary code on the affected systems. A vulnerability management solution can remediate th...

Sep 8, 2021By Vijay Chachadi2 min read

 Zoho Patches Critical Zero-day Flaw in ADSelfService to patch a remote code execution (RCE) vulnerability existing in Zoho ADSelfService plus. The vulnerability allows the execution of unauthenticated remote arbitrary code on the affected systems. A vulnerability management solution can remediate this vulnerability. As per the alert of the US Cyber Security and Infrastructure Security Agency (CISA), the vulnerability exploited in the wild.

Vulnerability Details

  • CVE-2021-40539: A remote code execution vulnerability exists in ADSelfService plus of Zoho

The flaw assigned with the identifier CVE-2021-40539. The severity score is not yet calculated by NIST but is considered as Critical as it allows unauthenticated RCE on systems with vulnerable ADSelfService plus. A patch management tool can patch this critical vulnerability.

The vulnerability triggered by sending a specially crafted request to the REST API endpoint of ADSelfService plus. As a result, an attacker can perform unauthenticated RCE on the affected systems.

Way to Identify if it affects the installation

As per the advisory of Zoho Corp, look for access log entries with the following strings in \ManageEngine\ADSelfService Plus\log folder:

  1. /RestAPI/LogonCustomization
  2. /RestAPI/Connection

The system affected if any of these entries are present in the logs

Affected Versions

Zoho ADSelfService plus versions before 6114.

Solution

Zoho Patches Critical Zero-day Flaw in ADSelfService in version 6114 or later.

The vulnerable versions of ADSelfService plus advised to update to the latest available release.

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