CVE-2021-20484Network attack vector

Trusted-session script execution via embedded JavaScript

Published Sep 23, 2021 · Updated Sep 16, 2024

Cross-site scripting in IBM Sterling File Gateway 2.2.0.0 through 6.1.0.3 allows remote authenticated users to expose credentials via its Web UI. The Web UI embeds attacker-supplied JavaScript without adequate neutralization, causing that code to execute in another user's trusted session. Exploitation requires low-privileged access and another user's interaction, and can alter displayed behavior or disclose that session's credentials.

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 Sterling File Gateway 2.2.0.0 through 6.1.0.3 allows remote authenticated users to expose credentials via its Web UI. The Web UI embeds attacker-supplied JavaScript without adequate neutralization, causing that code to execute in another user's trusted session. Exploitation requires low-privileged access and another user's interaction, and can alter displayed behavior or disclose that session's credentials.

The record

CVE
CVE-2021-20484
Published
Sep 23, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM Sterling File Gateway
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 23, 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=6.1.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM Sterling File Gatewayversion=2.2.0.0; version=6.1.0.3

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.2IBMCVSS:3.0/UI:R/C:L/I:L/AC:L/A:N/PR:L/S:C/AV:N/E:H/RL:O/RC:C

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')
T1189Drive-by Compromise

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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