CVE-2021-22523Network attack vector

Session hijacking via undisclosed XML processing flaw

Published Jul 22, 2021 · Updated Aug 3, 2024

XML external entity processing in Micro Focus Verastream Host Integrator 7.8 Update 1 and earlier allows remote attackers to hijack user sessions. The vendor has not disclosed the affected XML-processing component or how crafted XML results in JavaScript execution in the application context. Exploitation requires victim action, such as following an attacker-supplied link, and can control the browser, redirect navigation, or capture keystrokes.

CVSS severity8.2
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML external entity processing in Micro Focus Verastream Host Integrator 7.8 Update 1 and earlier allows remote attackers to hijack user sessions. The vendor has not disclosed the affected XML-processing component or how crafted XML results in JavaScript execution in the application context. Exploitation requires victim action, such as following an attacker-supplied link, and can control the browser, redirect navigation, or capture keystrokes.

The record

CVE
CVE-2021-22523
Published
Jul 22, 2021
Updated
Aug 3, 2024
Vendor
Micro Focus
Product
Verastream Host Integrator
Classifications
CWE-611, CAPEC-221, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=Version 7.8 Update 1 and earlier versions.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Micro Focus · Verastream Host Integratorversion=Version 7.8 Update 1 and earlier versions.

Published CVSS scores

7.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:L
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.2Micro FocusCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

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-611Improper Restriction of XML External Entity Reference
CAPEC-221Data Serialization External Entities Blowup
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

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Your stack

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