CVE-2023-3042
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 · uneditedIn dotCMS, versions mentioned, a flaw in the NormalizationFilter does not strip double slashes (//) from URLs, potentially enabling bypasses for XSS and access controls. An example affected URL is https://demo.dotcms.com//html/portlet/ext/files/edit_text_inc.jsp , which should return a 404 response but didn't. The oversight in the default invalid URL character list can be viewed at the provided GitHub link https://github.com/dotCMS/core/blob/master/dotCMS/src/main/java/com/dotcms/filters/NormalizationFilter.java#L37 . To mitigate, users can block URLs with double slashes at firewalls or utilize dotCMS config variables. Specifically, they can use the DOT_URI_NORMALIZATION_FORBIDDEN_STRINGS environmental variable to add // to the list of invalid strings. Additionally, the DOT_URI_NORMALIZATION_FORBIDDEN_REGEX variable offers more detailed control, for instance, to block //html.* URLs. Fix Version:23.06+, LTS 22.03.7+, LTS 23.01.4+
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 NormalizationFilter in dotCMS fails to strip double slashes (//) from URLs, allowing malicious URLs like //html/portlet/ext/files/edit_text_inc.jsp to bypass security controls. This enables potential XSS attacks and access control bypasses by circumventing path-based security restrictions.
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= 5.3.8= 21.06= 22.03= 23.01CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 the installed dotCMS versionAccess the dotCMS admin dashboard and navigate to System > Information, or check the version.properties file in the installation directory. Alternatively, check the response header or about page.Affected if The installed version is 5.3.8, 21.06, 22.03, or 23.01 exactly.
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Locate the NormalizationFilter configurationCheck the web.xml or the filter configuration files in the dotCMS deployment for a filter class named NormalizationFilter or URI normalization settings.Affected if NormalizationFilter is present and loaded in the filter chain.
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Test URL normalization behavior with double-slash URLsSend a request to the dotCMS server with a URL containing double slashes, such as //html/portlet/ext/files/edit_text_inc.jsp or //etc/passwd, and observe whether the server normalizes or blocks the request.Affected if The double-slash URL is not normalized to a single slash and is processed by the application.
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Inspect the forbidden strings configurationCheck for environment variables DOT_URI_NORMALIZATION_FORBIDDEN_STRINGS or DOT_URI_NORMALIZATION_FORBIDDEN_REGEX in the server environment or startup scripts.Affected if The forbidden strings list does not include // and there is no regex pattern blocking //html.* URLs.
A user is affected if their dotCMS version is exactly 5.3.8, 21.06, 22.03, or 23.01 and the NormalizationFilter does not strip or block double-slash URL patterns.
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 · scopedAdd // to the forbidden strings list using the DOT_URI_NORMALIZATION_FORBIDDEN_STRINGS environment variable, or use DOT_URI_NORMALIZATION_FORBIDDEN_REGEX to block specific patterns like //html.* URLs. Alternatively, block double-slash URLs at the firewall level.
Upgrade to DotCMS 23.06 or higher, or LTS 22.03.7+, or LTS 23.01.4+
- 1. Identify current DotCMS version by checking the admin dashboard or configuration files
- 2. Plan upgrade to one of the fixed releases: 23.06 (standard), LTS 22.03.7 (long-term support), or LTS 23.01.4 (long-term support)
- 3. Backup the current database and dotCMS installation directory
- 4. Stop the DotCMS application server
- 5. Follow the official upgrade documentation for your target version
- 6. Start the DotCMS server and verify the application loads correctly
- 7. Test that URLs with double slashes (e.g., //html/) now return 404 responses as expected
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-3042 — 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-2023-3042 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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- 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
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