CVE-2021-43892Network attack vector

Sensitive data disclosure via ESB.Portal cross-site scripting

Published Dec 15, 2021 · Updated Aug 4, 2024

Cross-site scripting in Microsoft BizTalk ESB Toolkit 2.2 through 2.4 allows remote attackers to read sensitive data via ESB.Portal. Microsoft identifies the ESB.Portal sample application and an open redirect but does not disclose the untrusted input, affected page, or unsafe output operation. Exploitation requires user interaction with attacker-controlled content; the reported consequence is confidentiality loss without data modification or service interruption.

CVSS severity7.4
High
EPSS probability2.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site scripting in Microsoft BizTalk ESB Toolkit 2.2 through 2.4 allows remote attackers to read sensitive data via ESB.Portal. Microsoft identifies the ESB.Portal sample application and an open redirect but does not disclose the untrusted input, affected page, or unsafe output operation. Exploitation requires user interaction with attacker-controlled content; the reported consequence is confidentiality loss without data modification or service interruption.

The record

CVE
CVE-2021-43892
Published
Dec 15, 2021
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Microsoft BizTalk ESB Toolkit
Classifications
T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0 <2.2
  2. Affected versionversion=2.0 <2.3
  3. Affected versionversion=2.4 <2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft BizTalk ESB Toolkitversion=2.0 <2.2; version=2.0 <2.3; version=2.4 <2.4

Published CVSS scores

7.4NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
7.4MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
4.3NVDAV:N/AC:M/Au:N/C:P/I:N/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

T1203Exploitation for Client Execution

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo