CVE-2020-28653Public exploitNetwork attack vector

Unauthenticated code execution via unsafe PDU deserialization

Published Feb 3, 2021 · Updated Aug 4, 2024

Unsafe deserialization in ManageEngine OpManager Stable builds before 125203 and Released builds before 125233 lets remote attackers execute code. SUMCommunicationServlet accepts unauthenticated sessions, and SUMPDU.deSerializePDU passes attacker-controlled bytes to ObjectInputStream.readObject without restricting classes. A crafted gadget chain executes commands as root on Linux or Administrator on Windows; no user interaction is required.

CVSS severity9.8
Critical
EPSS probability78.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in ManageEngine OpManager Stable builds before 125203 and Released builds before 125233 lets remote attackers execute code. SUMCommunicationServlet accepts unauthenticated sessions, and SUMPDU.deSerializePDU passes attacker-controlled bytes to ObjectInputStream.readObject without restricting classes. A crafted gadget chain executes commands as root on Linux or Administrator on Windows; no user interaction is required.

The record

CVE
CVE-2020-28653
Published
Feb 3, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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