CVE-2021-20397Network attack vector

Credential disclosure via injected Web UI JavaScript

Published May 5, 2021 · Updated Sep 16, 2024

Cross-site scripting in IBM QRadar SIEM 7.3 and 7.4 allows remote attackers to execute JavaScript in a trusted Web UI session. IBM does not disclose the affected Web UI page or parameter, or the input-neutralization failure that permits the script injection. Exploitation requires a user to interact with crafted content; executed script can alter Web UI behavior and expose credentials within that user’s trusted session.

CVSS severity6.1
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in IBM QRadar SIEM 7.3 and 7.4 allows remote attackers to execute JavaScript in a trusted Web UI session. IBM does not disclose the affected Web UI page or parameter, or the input-neutralization failure that permits the script injection. Exploitation requires a user to interact with crafted content; executed script can alter Web UI behavior and expose credentials within that user’s trusted session.

The record

CVE
CVE-2021-20397
Published
May 5, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
QRadar SIEM
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 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=7.3
  2. Affected versionversion=7.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · QRadar SIEMversion=7.3; version=7.4

Published CVSS scores

6.1IBM CorporationCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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