CVE-2021-27777Network attack vector

Unauthorized data modification via external entity injection

Published May 12, 2022 · Updated Sep 16, 2024

XML injection in HCL Unica Platform 12 and earlier allows remote attackers to alter processed XML via external entity references. HCL identifies a poorly configured XML parser that processes user-supplied XML without sufficient validation, but does not disclose the parser, endpoint, or code path. Network access and no authentication are required; the published assessment limits the reported consequence to unauthorized modification of processed data.

CVSS severity7.5
High
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML injection in HCL Unica Platform 12 and earlier allows remote attackers to alter processed XML via external entity references. HCL identifies a poorly configured XML parser that processes user-supplied XML without sufficient validation, but does not disclose the parser, endpoint, or code path. Network access and no authentication are required; the published assessment limits the reported consequence to unauthorized modification of processed data.

The record

CVE
CVE-2021-27777
Published
May 12, 2022
Updated
Sep 16, 2024
Vendor
HCL Software
Product
HCL Unica Platform
Classifications
CWE-611, CWE-91, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 12, 2022CVE 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=12 and below

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HCL Software · HCL Unica Platformversion=12 and below

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
7.5HCL SoftwareCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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

CWE-611Improper Restriction of XML External Entity Reference
CWE-91XML Injection (aka Blind XPath Injection)
T1190Exploit Public-Facing Application

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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