GHSA-prf8-cf2x-rhx7 — fabric-sdk-java
GHSA-prf8-cf2x-rhx7 is a Deserialization of Untrusted Data vulnerability in org.hyperledger.fabric-sdk-java:fabric-sdk-java. No vendor fix is recorded yet; mitigation options are listed below.
fabric-sdk-java has ObjectInputStream.readObject() without ObjectInputFilter, which allows Java deserialization RCE
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-prf8-cf2x-rhx7.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
org.hyperledger.fabric-sdk-java:fabric-sdk-javaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
This advisory covers the deprecated fabric-sdk-java client SDK. Channel.java implements readObject() and exposes deSerializeChannel() which call ObjectInputStream.readObject() on untrusted byte arrays without configuring an ObjectInputFilter. This is the classic Java deserialization RCE pattern.
Note: fabric-sdk-java is deprecated and maintained in https://github.com/hyperledger/fabric-sdk-java. Filing here as that repo does not have private vulnerability reporting enabled.
Affected Code
// src/main/java/org/hyperledger/fabric/sdk/Channel.java
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject(); // No ObjectInputFilter configured
}
public Channel deSerializeChannel(byte[] channelBytes)
throws IOException, ClassNotFoundException, InvalidArgumentException {
ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(channelBytes));
Channel channel = (Channel) ois.readObject(); // Untrusted bytes deserialized
return channel;
}
Attack Vector
An attacker who can supply crafted serialized Channel bytes to the client application — for example, by compromising a local channel file, injecting data through an application that accepts Channel bytes from external sources, or exploiting a separate write primitive — can achieve RCE via gadget chain exploitation when deSerializeChannel() processes those bytes. The risk is highest in deployments that accept Channel data from sources outside the client's direct control. Note: channel data is not transmitted from Fabric peers; this is a client-side deserialization surface.
Proof of Concept
// Generate malicious payload with ysoserial:
// java -jar ysoserial.jar CommonsCollections6 "touch /tmp/pwned" > malicious_channel.ser
// Victim code:
byte[] maliciousBytes = Files.readAllBytes(Paths.get("malicious_channel.ser"));
Channel channel = client.deSerializeChannel(maliciousBytes); // RCE fires here
Notes on Deprecation
fabric-sdk-java is deprecated as of Hyperledger Fabric v2.5 (replaced by org.hyperledger.fabric:fabric-gateway). However, organizations that have not yet migrated remain fully exposed. Automated dependency scanners (Snyk, Dependabot) cannot alert users without a published GHSA. This advisory is filed to ensure those users are notified and directed to migrate.
Fix
For the deprecated SDK: add ObjectInputFilter to whitelist only expected classes:
ObjectInputFilter filter = ObjectInputFilter.Config.createFilter(
"org.hyperledger.fabric.sdk.*;java.util.*;java.lang.*;!*"
);
ois.setObjectInputFilter(filter);
The recommended remediation is migration to org.hyperledger.fabric:fabric-gateway, which does not use Java serialization.
Resources
- CWE-502: Deserialization of Untrusted Data
- Migration guide: https://hyperledger.github.io/fabric-gateway/
Credits
Found by Martin Brodeur (brodmart) via independent security research.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.hyperledger.fabric-sdk-java:fabric-sdk-java | ≥ 1.0.0 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.hyperledger.fabric-sdk-java:fabric-sdk-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of org.hyperledger.fabric-sdk-java:fabric-sdk-java has shipped for GHSA-prf8-cf2x-rhx7 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-prf8-cf2x-rhx7 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-prf8-cf2x-rhx7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-prf8-cf2x-rhx7 in your dependencies?
O3 Security finds GHSA-prf8-cf2x-rhx7 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.