CVE-2020-4450Public exploitNetwork attack vector

Unauthenticated code execution via IIOP deserialization

Published Jun 5, 2020 · Updated Sep 16, 2024

Deserialization of untrusted data in IBM WebSphere Application Server traditional 8.5 and 9.0 allows remote attackers to execute arbitrary code. The IIOP protocol handler fails to validate user-supplied serialized objects before deserializing them. No authentication or user interaction is required, and successful exploitation runs code in the server process context.

CVSS severity9.8
Critical
EPSS probability34.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in IBM WebSphere Application Server traditional 8.5 and 9.0 allows remote attackers to execute arbitrary code. The IIOP protocol handler fails to validate user-supplied serialized objects before deserializing them. No authentication or user interaction is required, and successful exploitation runs code in the server process context.

The record

CVE
CVE-2020-4450
Published
Jun 5, 2020
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM WebSphere Application Server
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 5, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.5
  2. Affected versionversion=9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · IBM WebSphere Application Serverversion=8.5; version=9.0

Published CVSS scores

9.8IBMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
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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