Your RSA-2048 keys break in 2030. Find every one of them before attackers do.

CVE-2021-37539

CRITICAL

CVE-2021-37539 is a critical-severity (CVSS 9.8) Unrestricted File Upload vulnerability in zohocorp manageengine admanager plus. O3 Security detects and blocks CVE-2021-37539 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

Zoho ManageEngine ADManager Plus before 7111 is vulnerable to unrestricted file which leads to Remote code execution.

Published
Sep 27, 2021
Updated
Jun 17, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed

Description

Zoho ManageEngine ADManager Plus before 7111 is vulnerable to unrestricted file which leads to Remote code execution.

Affected Products

1 product · 6 configurations
Application
manageengine admanager pluszohocorp
< 7.1
1 version
7.1

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every zohocorp manageengine admanager plus deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Fix

    Apply the zohocorp manageengine admanager plus security patch or hotfix for CVE-2021-37539 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2021-37539 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2021-37539. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Zoho ManageEngine ADManager Plus before 7111 is vulnerable to unrestricted file which leads to Remote code execution.
O3 Security · Runtime Protection

Is CVE-2021-37539 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-37539 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.