CVE-2021-20561Network attack vector

Credential disclosure via executable Web UI content

Published Oct 7, 2021 · Updated Sep 16, 2024

Cross-site scripting in the myfilegateway UI of IBM Sterling File Gateway 2.2.0.0 through 6.1.1.0 allows remote authenticated users to expose credentials. The UI accepts attacker-supplied content and renders it as executable JavaScript, but IBM has not identified the affected request, parameter, or encoding failure. Exploitation requires low-privileged access and victim interaction within a trusted session, where the script can alter UI content and disclose session credentials.

CVSS severity5.4
Medium
EPSS probability0.64%
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 the myfilegateway UI of IBM Sterling File Gateway 2.2.0.0 through 6.1.1.0 allows remote authenticated users to expose credentials. The UI accepts attacker-supplied content and renders it as executable JavaScript, but IBM has not identified the affected request, parameter, or encoding failure. Exploitation requires low-privileged access and victim interaction within a trusted session, where the script can alter UI content and disclose session credentials.

The record

CVE
CVE-2021-20561
Published
Oct 7, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM Sterling File Gateway
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 7, 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=2.2.0.0
  2. Affected versionversion=5.2.6.5_4
  3. Affected versionversion=6.0.0.0
  4. Affected versionversion=6.0.0.6
  5. Affected versionversion=6.0.1.0
  6. Affected versionversion=6.0.3.4
  7. Affected versionversion=6.1.0.0
  8. Affected versionversion=6.1.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM Sterling File Gatewayversion=2.2.0.0; version=5.2.6.5_4; version=6.0.0.0; version=6.0.0.6; version=6.0.1.0; version=6.0.3.4; version=6.1.0.0; version=6.1.0.2

Published CVSS scores

5.4IBMCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.2IBMCVSS:3.0/PR:L/AC:L/I:L/AV:N/A:N/UI:R/S:C/C:L/RL:O/RC:C/E: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

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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