CVE-2021-27777
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedXML External Entity (XXE) injection vulnerabilities occur when poorly configured XML parsers process user supplied input without sufficient validation. Attackers can exploit this vulnerability to manipulate XML content and inject malicious external entity references.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceXXE injection vulnerability where the XML parser processes user-supplied input without proper validation, allowing attackers to inject malicious external entity references to access local files, perform SSRF, or denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 12.1.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed HCL Unica versionLocate the Unica installation directory and check version information files, typically found in the installation root or via the product's version/about dialogAffected if The installed version is lower than 12.1.1
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Determine if XML processing features are in useReview application configuration files and check for XML import, data feed, or integration modules that process XML inputAffected if XML import, data feeds, or integration features that parse XML are enabled or configured
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Inspect XML parser configurationExamine XML parser settings in configuration files within the Unica installation, looking for settings related to entity processing and DTD handlingAffected if External entity processing and DTD processing are enabled in the XML parser configuration (no disabled entities or DTD restrictions)
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Check for user-supplied XML input handlingReview how the application handles XML uploads or XML data submitted through web interfaces, API endpoints, or import functionsAffected if The application accepts XML input from users without validation or sanitization
A user is affected if running HCL Unica version below 12.1.1 and the application processes XML input with external entity processing enabled.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped12.1.1
Disable external entity processing and DTD processing in XML parsers, enable secure processing features, and implement input validation before XML parsing.
Unica 12.1.1
- Identify the current installed version of HCL Unica
- Backup all Unica configurations, databases, and customizations
- Review HCL Unica 12.1.1 release notes for upgrade prerequisites
- Plan maintenance window for the upgrade process
- Stop all Unica services and listeners
- Upgrade Unica to version 12.1.1 following HCL's official upgrade documentation
- After upgrade, validate that all services start correctly
- Verify the XXE vulnerability is resolved by testing XML parsing functionality
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-27777 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-27777 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data