CVE-2021-20492Network attack vector

Information disclosure and memory exhaustion via XXE

Published May 26, 2021 · Updated Sep 16, 2024

XXE in IBM WebSphere Application Server Java Batch 8.0, 8.5, 9.0, and Liberty allows remote attackers to read sensitive data. The Java Batch XML-processing path accepts external entity references, but IBM has not disclosed the parser, entry point, or missing hardening control. Network access without authentication is sufficient; crafted XML can disclose server-accessible information or consume memory and impair availability.

CVSS severity6.5
Medium
EPSS probability2.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in IBM WebSphere Application Server Java Batch 8.0, 8.5, 9.0, and Liberty allows remote attackers to read sensitive data. The Java Batch XML-processing path accepts external entity references, but IBM has not disclosed the parser, entry point, or missing hardening control. Network access without authentication is sufficient; crafted XML can disclose server-accessible information or consume memory and impair availability.

The record

CVE
CVE-2021-20492
Published
May 26, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM WebSphere Application Server
Classifications
CWE-611, T1005, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2021CVE 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=8.0
  2. Affected versionversion=8.5
  3. Affected versionversion=9.0
  4. Affected versionversion=Liberty

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · IBM WebSphere Application Serverversion=8.0; version=8.5; version=9.0; version=Liberty

Published CVSS scores

6.4NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:P
6.5IBM CorporationCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
8.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1005Data from Local System
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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