CVE-2025-24970: Netty Framework Native Crash DoS Flaw

CVE-2025-24970 Overview

Netty, an asynchronous, event-driven network application framework, presents a vulnerability starting in version 4.1.91.Final and prior to version 4.1.118.Final. The issue arises when a specially crafted packet is received via SslHandler. This can lead to improper handling and cause a native crash.

Critical Impact
This vulnerability can result in a denial of service condition, impacting applications using the affected versions.

Affected Products

netty netty
netapp active_iq_unified_manager
netapp oncommand_insight

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to netty
Not Available - CVE CVE-2025-24970 assigned
Not Available - netty releases security patch
2025-02-10 - CVE CVE-2025-24970 published to NVD
2025-09-05 - Last updated in NVD database

Technical Details for CVE-2025-24970

Vulnerability Analysis

The vulnerability is caused by improper validation of packets when processed by the SslHandler in Netty's framework. This can result in a scenario where a malformed packet leads to a crash, due to how native resources are managed.

Root Cause

The root cause lies in the inadequate validation logic within the SslHandler component, which fails to safeguard against malformed packets, allowing for conditions that can crash the service.

Attack Vector

The primary attack vector is over the network, where an attacker sends a malformed packet to services using vulnerable versions of Netty.

java

// Example exploitation setup
SSLEngine sslEngine = ...; // Configure SSLEngine
data = constructMaliciousPacket();
sslEngine.unwrap(data, ...); // This call can trigger the crash

Detection Methods for CVE-2025-24970

Indicators of Compromise

Unexplained application crashes
Logs showing exceptions in SslHandler
Abnormal traffic patterns

Detection Strategies

Utilize application monitoring tools to detect anomalies in traffic and application behavior associated with SslHandler. Alert on unusual exceptions and crash logs.

Monitoring Recommendations

Set up real-time monitoring for packet anomalies and exceptions specifically related to SSL traffic processing. Use tools like SentinelOne to automate detection and respond to such incidents.

How to Mitigate CVE-2025-24970

Immediate Actions Required

Upgrade to Netty version 4.1.118.Final or later.
Implement network-level monitoring to block suspicious packet patterns.
Review application logs regularly for anomalies.

Patch Information

The patch resolving this issue is included in Netty version 4.1.118.Final. Affected users are encouraged to upgrade immediately.

Workarounds

As a temporary measure, users can disable the usage of the native SSLEngine or adjust the handling code manually to validate packet integrity before processing.

bash

# Configuration example to disable native SSLEngine
-Djavax.net.ssl.engine=openssl