RollerApplication · Apache
CVE-2021-33580
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 · uneditedUser controlled `request.getHeader("Referer")`, `request.getRequestURL()` and `request.getQueryString()` are used to build and run a regex expression. The attacker doesn't have to use a browser and may send a specially crafted Referer header programmatically. Since the attacker controls the string and the regex pattern he may cause a ReDoS by regex catastrophic backtracking on the server side. This problem has been fixed in Roller 6.0.2.
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 confidenceApache Roller uses user-controlled input from request.getHeader('Referer'), request.getRequestURL(), and request.getQueryString() to construct regex patterns without sanitization. An attacker can provide a malicious regex pattern causing catastrophic backtracking (ReDoS), leading to 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
RollerApplication
< 6.0.2CVSS 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
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Identify Apache Roller installationSearch for Apache Roller files in your application directory: look for 'roller' in WAR files, JAR files, or application logs. Check your web application server (Tomcat, Jetty, etc.) deployments for roller.war or roller-related files.Affected if Apache Roller is found in your environment
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Determine Apache Roller versionCheck the version by inspecting: 1) The roller.war or roller JAR file name if present, 2) The MANIFEST.MF file inside the WAR, 3) The application startup logs that typically display the Roller version, 4) Any version.txt or about page within the Roller application.Affected if The installed version is lower than 6.0.2 (e.g., 6.0.0, 5.2.2, 5.1.0, etc.)
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Verify web exposureCheck your web server or application server configuration (server.xml for Tomcat, etc.) to determine if the Roller application is bound to a network-accessible IP address (0.0.0.0 or public IP) and open port, rather than localhost only.Affected if The Roller application is accessible over the network (not localhost-only)
Your environment is affected if Apache Roller version 6.0.2 or later is NOT installed AND the application is network-accessible, allowing attackers to send malicious Referer headers, URLs, or query strings to trigger the ReDoS.
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 · scoped6.0.2
Upgrade to Apache Roller 6.0.2 or later, or implement strict input validation to ensure only expected patterns are used in regex construction.
Roller 6.0.2
- Upgrade Apache Roller to version 6.0.2 or later to resolve the ReDoS vulnerability
- After upgrading, verify that the Referer header handling works correctly in your Roller installation
- Test that blog rendering and trackback/pingback functionality (which use the Referer header) continue to work as expected
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Roller
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 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 $3,168.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33580 — 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-2021-33580 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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