CVE-2023-4612
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 · uneditedImproper Authentication vulnerability in Apereo CAS in jakarta.servlet.http.HttpServletRequest.getRemoteAddr method allows Multi-Factor Authentication bypass.This issue affects CAS: through 7.0.0-RC7. It is unknown whether in new versions the issue will be fixed. For the date of publication there is no patch, and the vendor does not treat it as a vulnerability.
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 confidenceThe vulnerability allows attackers to spoof their apparent IP address via the jakarta.servlet.http.HttpServletRequest.getRemoteAddr method in Apereo CAS, bypassing IP-based Multi-Factor Authentication controls. This is an improper authentication issue where the server trusts the client-reported remote address without proper validation.
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< 7.0.0= 7.0.0CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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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Determine CAS versionLocate the CAS build or WAR file and identify the installed version, typically found in build.properties, manifest.mf, or the cas.war file name. Compare this version against the affected range: versions < 7.0.0 or exactly 7.0.0 are vulnerable.Affected if Installed CAS version is 7.0.0 or any version below 7.0.0
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Identify IP-based MFA configurationReview CAS configuration files (application.properties, cas.properties, or XML configuration) for settings related to IP-based authentication, such as mfa.IP, authentication.policy.ip, or similar IP-based conditional authentication rules.Affected if IP-based MFA or IP-conditional authentication is configured in CAS
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Verify reverse proxy handlingInspect the CAS deployment configuration to determine if a reverse proxy or load balancer is in the request path, and check whether X-Forwarded-For headers are being used to determine the client IP address.Affected if X-Forwarded-For headers are used to determine client IP without validation
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Check for client IP validation in request handlingExamine the CAS web.xml or filter configuration to see how HttpServletRequest.getRemoteAddr is being used for authentication decisions, particularly in MFA or access control filters.Affected if getRemoteAddr is used directly for MFA or access control decisions without additional validation
A user is affected if running CAS version 7.0.0 or below AND IP-based MFA or IP-based authentication controls are configured using the client-reported remote address.
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 data7.0.0
Implement additional authentication layers not reliant on spoofable IP detection, such as certificate-based MFA, hardware tokens, or configure reverse proxies to enforce genuine client source IP validation at the network edge.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-4612 — 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-2023-4612 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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