CVE-2021-20365Network attack vector

Credential disclosure via target-blank anchor script injection

Published Jul 13, 2021 · Updated Sep 16, 2024

Cross-site scripting in IBM Cloud Pak for Applications 4.3 allows remote authenticated users to disclose credentials through its Web UI. IBM identifies HTML anchors using target=_blank as the flaw locus but does not publish the exact sanitization error that permits embedded JavaScript. Exploitation requires low-privilege access to store the payload and user interaction to open the crafted link; reported effects are credential disclosure and Web UI alteration.

CVSS severity5.4
Medium
EPSS probability0.50%
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 Cloud Pak for Applications 4.3 allows remote authenticated users to disclose credentials through its Web UI. IBM identifies HTML anchors using target=_blank as the flaw locus but does not publish the exact sanitization error that permits embedded JavaScript. Exploitation requires low-privilege access to store the payload and user interaction to open the crafted link; reported effects are credential disclosure and Web UI alteration.

The record

CVE
CVE-2021-20365
Published
Jul 13, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM Cloud Pak for Applications
Classifications
CWE-79
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 13, 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=4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM Cloud Pak for Applicationsversion=4.3

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.4IBMCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/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
Privilegesauthenticated
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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