Openvpn Access ServerApplication · Openvpn
CVE-2020-11462
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 · uneditedAn issue was discovered in OpenVPN Access Server before 2.7.0 and 2.8.x before 2.8.3. With the full featured RPC2 interface enabled, it is possible to achieve a temporary DoS state of the management interface when sending an XML Entity Expansion (XEE) payload to the XMLRPC based RPC2 interface. The duration of the DoS state depends on available memory and CPU speed. The default restricted mode of the RPC2 interface is NOT vulnerable.
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 confidenceOpenVPN Access Server versions before 2.7.0 and 2.8.x before 2.8.3 are vulnerable to XML Entity Expansion (XEE) attacks against the XMLRPC-based RPC2 interface when the full featured mode is enabled. This XML bomb attack causes excessive resource consumption during parsing, leading to a temporary denial of service of the management interface. The default restricted mode is not vulnerable.
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
Openvpn Access ServerApplication
< 2.7.0>= 2.8.0, <= 2.8.3CVSS 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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Determine OpenVPN Access Server versionRun 'openvpn --version' or check the admin web interface for the server versionAffected if Version is less than 2.7.0, or version is 2.8.0 through 2.8.3
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Identify RPC2 interface modeExamine the RPC2 configuration for the 'full_featured' or 'restricted' mode setting. This is typically found in the server configuration or admin panel under the RPC2 interface settings.Affected if The RPC2 interface is set to full featured mode (not the default restricted mode)
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Confirm XMLRPC interface is exposedVerify that the XMLRPC-based RPC2 interface is accessible and enabled on the management interface.Affected if The RPC2 XMLRPC interface is exposed and active
A system is affected only if it runs OpenVPN Access Server version < 2.7.0 or between 2.8.0 and 2.8.3 AND has the RPC2 interface configured in full featured mode rather than the default restricted mode.
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 data2.7.0
Upgrade to OpenVPN Access Server 2.7.0 / 2.8.3 or later, or ensure the RPC2 interface remains in its default restricted mode rather than enabling the full featured mode.
Fix this in Openvpn Access Server
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-11462 — 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-2020-11462 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
- No spam, self-promotion, credentials, or personal data