StrutsFramework / library · Apache
CVE-2016-4465
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 · uneditedThe URLValidator class in Apache Struts 2 2.3.20 through 2.3.28.1 and 2.5.x before 2.5.1 allows remote attackers to cause a denial of service via a null value for a URL field.
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 · high confidenceThe URLValidator class in Apache Struts 2 versions 2.3.20 through 2.3.28.1 and 2.5.x before 2.5.1 does not properly handle null values for URL fields, allowing remote attackers to cause a denial of service by submitting a null URL value that triggers an infinite loop or resource exhaustion in the validation logic.
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
StrutsFramework / library
= 2.3.20= 2.3.20.1= 2.3.20.3= 2.3.24= 2.3.24.1= 2.3.24.3= 2.3.28= 2.3.28.1= 2.5CVSS 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
- None
- Availability
- Low
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 Apache Struts 2 installationLocate the Struts2 library JAR files (e.g., struts2-core-*.jar) in your application WEB-INF/lib directory or project dependencies, and note the version number from the filenameAffected if The installed version is 2.3.20, 2.3.20.1, 2.3.20.3, 2.3.24, 2.3.24.1, 2.3.24.3, 2.3.28, 2.3.28.1, or any 2.5.x version before 2.5.1
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Confirm URLValidator is in useSearch your Struts XML configuration files (struts.xml) or annotation-based configurations for <validator> elements referencing URLValidator, or look for fields validated using the url validation typeAffected if URLValidator is configured to validate URL-type fields in your application
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Check for nullable URL input fieldsReview your action forms or domain objects for String-type fields that accept URL input and are validated by URLValidator, and determine if these fields can accept null or empty values from HTTP requestsAffected if URL-validated fields can receive null or empty values from user input without prior validation
You are affected if your application runs a Struts 2 version between 2.3.20 and 2.3.28.1 or 2.5.x before 2.5.1, uses URLValidator on fields that can accept null URL values from user input.
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.
From vendor dataUpgrade Apache Struts 2 to version 2.3.28.2 or 2.5.1 or later, which contains the fix for proper null handling in URLValidator. Alternatively, implement input validation to reject null/empty URL values before they reach the URLValidator.
Fix this in Struts
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-4465 — 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-2016-4465 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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- Version or environment caveats, and links to real fixes
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