# CVE-2020-28653: ManageEngine OpManager - RCE

> Live exploitation tracking for CVE-2020-28653 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2020-28653

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Zoho ManageEngine OpManager
- **Tags:** enterprise_software

## Description

Zoho ManageEngine OpManager Stable build before 125203 (and Released build before 125233) allows Remote Code Execution via the Smart Update Manager (SUM) servlet.

## CrowdSec analysis

[CVE-2020-28653](https://euvd.enisa.europa.eu/vulnerability/CVE-2020-28653) is a critical remote code execution vulnerability in Zoho ManageEngine OpManager versions prior to Stable build 125203 and Released build 125233, exploitable via the Smart Update Manager (SUM) servlet. Attackers can leverage this flaw to execute arbitrary code on the affected server without authentication, potentially leading to full system compromise.

CrowdSec has been tracking this vulnerability and its exploits since 15th of October 2025.

CrowdSec has not observed any significant exploitation activity targeting CVE-2020-28653 across its network. As a result, no community-driven trend analysis is available for this vulnerability at this time.

Attackers exploit the vulnerable SUM servlets by sending crafted POST requests to endpoints such as `/servlets/com.adventnet.tools.sum.transport.SUMCommunicationServlet` and `/servlets/com.adventnet.tools.sum.transport.SUMHandShakeServlet` to trigger Java deserialization and achieve remote code execution.

## Timeline

- 2021-02-03: CVE Published. CVE-2020-28653 is published to NVD.
- 2025-10-15: Rule Released. CrowdSec releases a rule to detect CVE-2020-28653 exploitation attempts against the CrowdSec Network.
- 2025-10-28: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2020-28653 for the first time.

## References

- http://packetstormsecurity.com/files/164231/ManageEngine-OpManager-SumPDU-Java-Deserialization.html
- https://www.manageengine.com/network-monitoring/help/read-me-complete.html#125203
- https://www.manageengine.com/network-monitoring/help/read-me-complete.html#125233
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-28653.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2020-28653) follows observed exploitation activity for CVE-2020-28653. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.