Tomcat Jk ConnectorWeb server / proxy · Apache
CVE-2018-1323
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 IIS/ISAPI specific code in the Apache Tomcat JK ISAPI Connector 1.2.0 to 1.2.42 that normalised the requested path before matching it to the URI-worker map did not handle some edge cases correctly. If only a sub-set of the URLs supported by Tomcat were exposed via IIS, then it was possible for a specially constructed request to expose application functionality through the reverse proxy that was not intended for clients accessing Tomcat via the reverse proxy.
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 Apache Tomcat JK ISAPI Connector 1.2.0-1.2.42 contains a path normalization vulnerability in its IIS/ISAPI-specific code. When IIS exposes only a subset of Tomcat URLs, specially crafted requests can bypass the URI-worker map restrictions due to incorrect handling of edge cases in path normalization, exposing unintended application functionality through the reverse proxy.
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
Tomcat Jk ConnectorWeb server / proxy
>= 1.2.0, <= 1.2.42CVSS 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
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 JK ISAPI Connector versionLocate the isapi_redirect.dll file (typically in a bin/ or connector/ directory of the IIS server) and check its file properties for the version, or run 'strings isapi_redirect.dll | grep "mod_jk"' to find the version stringAffected if Version is 1.2.0 through 1.2.42 (inclusive)
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Confirm IIS is using JK connector for Tomcat proxyingCheck the IIS Manager for ISAPI filters pointing to the JK connector, or inspect the Windows registry under HKLM\Software\Apache Software Foundation\Jakarta Isapi Redirector for the worker_file configurationAffected if IIS is configured to load the JK ISAPI filter and forward requests to Tomcat
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Verify URI-worker map restricts exposed URLsOpen the worker properties file (uriworkermap.properties or similar, path specified in worker_file registry setting) and review the URI mappings defined thereAffected if A limited subset of URL paths is mapped while other paths are explicitly excluded or not mapped
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Test for path normalization bypassSend a crafted request through IIS to Tomcat using path sequences like /..;/ or multiple slashes that normalize to restricted paths, then verify whether access is granted to unmapped URIsAffected if Requests with manipulated path segments reach Tomcat endpoints that are not defined in the uriworkermap.properties
Affected if the JK ISAPI Connector version is 1.2.0-1.2.42 AND IIS is proxying requests to Tomcat with URI-worker map restrictions that can be bypassed via path normalization tricks.
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 the JK ISAPI Connector to version 1.2.43 or later. Alternatively, implement additional request validation at the IIS level to restrict access to only the intended URL patterns.
Fix this in Tomcat Jk Connector
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-1323 — 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-2018-1323 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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