GHSA-xq3w-v528-46rv is a medium-severity (CVSS 5.5) Uncontrolled Resource Consumption vulnerability in io.netty:netty-common. A fix is available for io.netty:netty-common — see the affected versions and patch details below.
Denial of Service attack on windows app using netty
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.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xq3w-v528-46rv.
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.
How urgent is this, really
GHSA-xq3w-v528-46rv plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
io.netty:netty-commonReal-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
An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash.
Details
When the library netty is loaded in a java windows application, the library tries to identify the system environnement in which it is executed.
At this stage, Netty tries to load both /etc/os-release and /usr/lib/os-release even though it is in a Windows environment.
If netty finds this files, it reads them and loads them into memory.
By default :
- The JVM maximum memory size is set to 1 GB,
- A non-privileged user can create a directory at
C:\and create files within it.
the source code identified : https://github.com/netty/netty/blob/4.1/common/src/main/java/io/netty/util/internal/PlatformDependent.java
Despite the implementation of the function normalizeOs() the source code not verify the OS before reading C:\etc\os-release and C:\usr\lib\os-release.
PoC
Create a file larger than 1 GB of data in C:\etc\os-release or C:\usr\lib\os-release on a Windows environnement and start your Netty application.
To observe what the application does with the file, the security analyst used "Process Monitor" from the "Windows SysInternals" suite. (https://learn.microsoft.com/en-us/sysinternals/)
cd C:\etc
fsutil file createnew os-release 3000000000
The source code used is the Netty website code example : Echo ‐ the very basic client and server.
The vulnerability was tested on the 4.1.112.Final version.
The security analyst tried the same technique for C:\proc\sys\net\core\somaxconn with a lot of values to impact Netty but the only things that works is the "larger than 1 GB file" technique. https://github.com/netty/netty/blob/c0fdb8e9f8f256990e902fcfffbbe10754d0f3dd/common/src/main/java/io/netty/util/NetUtil.java#L186
Impact
By loading the "file larger than 1 GB" into the memory, the Netty library exceeds the JVM memory limit and causes a crash in the java Windows application.
This behaviour occurs 100% of the time in both Server mode and Client mode if the large file exists.
Client mode :
<img width="449" alt="6" src="https://github.com/user-attachments/assets/f8fe1ed0-1a42-4490-b9ed-dbc9af7804be">Server mode :
<img width="464" alt="7" src="https://github.com/user-attachments/assets/b34b42bd-4fbd-4170-b93a-d29ba87b88eb">somaxconn :
<img width="532" alt="8" src="https://github.com/user-attachments/assets/0656b3bb-32c6-4ae2-bff7-d93babba08a3">Severity
- Attack vector : "Local" because the attacker needs to be on the system where the Netty application is running.
- Attack complexity : "Low" because the attacker only need to create a massive file (regardless of its contents).
- Privileges required : "Low" because the attacker requires a user account to exploit the vulnerability.
- User intercation : "None" because the administrator don't need to accidentally click anywhere to trigger the vulnerability. Furthermore, the exploitation works with defaults windows/AD settings.
- Scope : "Unchanged" because only Netty is affected by the vulnerability.
- Confidentiality : "None" because no data is exposed through exploiting the vulnerability.
- Integrity : "None" because the explotation of the vulnerability does not allow editing, deleting or adding data elsewhere.
- Availability : "High" because the exploitation of this vulnerability crashes the entire java application.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-common | all versions | 4.1.115.Finalio.netty:netty-common:4.1.115.Final |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-common, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty:netty-common to 4.1.115.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xq3w-v528-46rv is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-xq3w-v528-46rv can be triaged on real exposure rather than presence alone.
Tailored to GHSA-xq3w-v528-46rv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Quarkus 3.15.3 | quarkus-netty | RHSA-2025:0900 |
| Red Hat JBoss Enterprise Application Platform | io.netty/netty-common:4.1.124.Final-redhat-00001 | RHSA-2025:3467 |
| Red Hat JBoss Enterprise Application Platform 7.4.22 | io.netty/netty-common:4.1.119.Final-redhat-00004 | RHSA-2025:4552 |
| Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8 | eap7-netty-0:4.1.119-1.Final_redhat_00004.1.el8eap | RHSA-2025:3465 |
| Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8 | eap7-apache-commons-io-0:2.16.1-1.redhat_00001.1.el8eap | RHSA-2025:4549 |
| Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 9 | eap7-apache-commons-io-0:2.16.1-1.redhat_00001.1.el9eap | RHSA-2025:4550 |
| Red Hat JBoss Enterprise Application Platform 7.4 on RHEL 7 | eap7-apache-commons-io-0:2.16.1-1.redhat_00001.1.el7eap | RHSA-2025:4548 |
| Red Hat JBoss Enterprise Application Platform 8 | io.netty/netty | RHSA-2025:3358 |
Frequently Asked Questions
Is GHSA-xq3w-v528-46rv in your dependencies?
O3 Security finds GHSA-xq3w-v528-46rv across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.