DubboApplication · Apache
CVE-2020-11995
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 · uneditedA deserialization vulnerability existed in dubbo 2.7.5 and its earlier versions, which could lead to malicious code execution. Most Dubbo users use Hessian2 as the default serialization/deserialization protool, during Hessian2 deserializing the HashMap object, some functions in the classes stored in HasMap will be executed after a series of program calls, however, those special functions may cause remote command execution. For example, the hashCode() function of the EqualsBean class in rome-1.7.0.jar will cause the remotely load malicious classes and execute malicious code by constructing a malicious request. This issue was fixed in Apache Dubbo 2.6.9 and 2.7.8.
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 confidenceA deserialization vulnerability in Apache Dubbo 2.7.5 and earlier versions allows remote code execution through maliciously crafted Hessian2-serialized requests. When HashMap objects are deserialized, the hashCode() method of classes stored within (specifically EqualsBean from rome-1.7.0.jar) triggers a chain of calls that can be abused to dynamically load and execute arbitrary malicious classes remotely.
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
DubboApplication
>= 2.5.0, <= 2.5.10>= 2.6.0, <= 2.6.8>= 2.7.0, <= 2.7.7CVSS 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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Identify installed Apache Dubbo versionLocate the dubbo JAR file in your application lib directory or check pom.xml/build.gradle for the dubbo dependency version. Common paths: WEB-INF/lib/, lib/, or build output directories.Affected if The version is 2.5.0-2.5.10, 2.6.0-2.6.8, or 2.7.0-2.7.7
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Confirm Hessian2 serialization is enabledCheck your Dubbo configuration files (dubbo.properties, application.yml, dubbo.xml) for serialization settings. Look for entries like 'dubbo.serialization' set to 'hessian2' or check the default serialization configuration.Affected if Hessian2 serialization is explicitly enabled or is the default serialization protocol
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Verify vulnerable rome library is presentSearch for rome-1.7.0.jar or rome-1.7.x.jar in your application classpath or WEB-INF/lib directory. Also check Maven/Gradle dependencies for the rome library.Affected if rome library version 1.7.0 or 1.7.x is present in the classpath
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Check Dubbo service exposure configurationReview your Dubbo service definitions to confirm services are exposed over network protocols (dubbo, http, etc.). Check for @DubboService or <dubbo:service> configurations.Affected if Dubbo services are exposed to network listeners without additional serialization filters
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Inspect serialization filter settingsCheck for serialization filter configuration in JVM arguments (-Ddubbo.application.serialization.filter) or in dubbo.properties/dubbo.xml under application or provider settings.Affected if No custom serialization filter is configured and the default Hessian2 deserialization is allowed
Your environment is affected if you run Apache Dubbo versions 2.5.0-2.5.10, 2.6.0-2.6.8, or 2.7.0-2.7.7 with Hessian2 serialization enabled and the rome-1.7.x library present in the classpath.
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 · scopedUpgrade Apache Dubbo to version 2.6.9, 2.7.8, or later to obtain the patched serialization handling. If immediate patching is not possible, consider disabling Hessian2 serialization or implementing serialization whitelist controls at the network boundary.
Dubbo 2.6.9+ or 2.7.8+ (2.5.x branch is unmaintained; migrate to 2.7.8+)
- 1. Identify your current Apache Dubbo version by checking your project dependencies (pom.xml, build.gradle, or application classpath)
- 2. For Dubbo 2.6.x users: Upgrade to Dubbo 2.6.9 or later
- 3. For Dubbo 2.7.x users: Upgrade to Dubbo 2.7.8 or later
- 4. For Dubbo 2.5.x users: Upgrade to at least Dubbo 2.7.8 (2.5.x is no longer maintained; 2.5.10 and below are all affected with no patch)
- 5. After upgrading, verify the Dubbo version in your runtime dependencies matches the target version
- 6. Test your application thoroughly to ensure the upgrade does not break existing functionality
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Dubbo
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,616.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-11995 — 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-2020-11995 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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