CVE-2021-27788Network attack vector

Victim-session script execution via crafted URL

Published Mar 10, 2023 · Updated Feb 27, 2025

Cross-site scripting in HCL Verse 2.x allows remote attackers to run script in a victim's browser through a crafted URL. HCL has not disclosed the affected URL parameter or the exact output-handling error that reflects attacker-controlled content. Exploitation requires a victim to click the link, after which the script can act within the victim's Verse session or read cookies and session tokens accessible to script.

CVSS severity8.3
High
EPSS probability0.57%
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 HCL Verse 2.x allows remote attackers to run script in a victim's browser through a crafted URL. HCL has not disclosed the affected URL parameter or the exact output-handling error that reflects attacker-controlled content. Exploitation requires a victim to click the link, after which the script can act within the victim's Verse session or read cookies and session tokens accessible to script.

The record

CVE
CVE-2021-27788
Published
Mar 10, 2023
Updated
Feb 27, 2025
Vendor
HCL Software
Product
HCL Verse
Classifications
CWE-79, T1539, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 2025Record 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.x

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HCL Software · HCL Verseversion=2.x

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
8.3HCL SoftwareCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie
T1204.001Malicious Link

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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