Netty
CVE-2023-34462
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource consumption limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.5 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could cause denial of service by exhausting system resources by sending crafted requests to the affected application. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAI
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Implement rate limiting, set resource quotas, validate input sizes, use timeouts.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Uncontrolled Resource Consumption (CWE-400), which allows attackers to cause denial of service by exhausting system resources. Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The SniHandler can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the SniHandler to allocate 16MB of heap. The SniHandler class is a handler that waits for the TLS handshake to configure a SslHandler according to the indicated server name by the ClientHello record. For this matter it allocates a ByteBuf using the value defined in the ClientHello record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the SslClientHelloHandler. This vulnerability has been fixed in version 4.1.94.Final. Affected products include: Netty. Version information: up to 16.
Know when Netty gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The SniHandler can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the SniHandler to allocate 16MB of heap. The SniHandler class is a handler that waits for the TLS handshake to configure a SslHandler according to the indicated server name by the ClientHello record. For this matter it allocates a ByteBuf using the value defined in the ClientHello record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the SslClientHelloHandler. This vulnerability has been fixed in version 4.1.94.Final.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked
Certificate revocation-check bypass in the Netty network framework's OCSP client (io.netty:netty-handler-ssl-ocsp) affec
netty-incubator-codec-ohttp is the OHTTP implementation for netty. Rated critical severity (CVSS 9.1), this vulnerabilit
The netty incubator codec.bhttp is a java language binary http parser. Rated high severity (CVSS 8.1), this vulnerabilit
Netty, an asynchronous, event-driven network application framework, has a vulnerability starting in version 4.1.91.Final
Memory exhaustion in Netty's SctpMessageCompletionHandler (netty-transport-sctp) allows unauthenticated remote peers to
Compression-amplification denial of service in the Netty network framework (versions prior to 4.1.136.Final and 4.2.16.F
Memory-amplification denial of service in the Netty network framework (SPDY/3.1 codec) prior to 4.1.136.Final and 4.2.16
Memory-exhaustion denial of service in Netty's HTTP/3 codec (Http3FrameCodec) affects all releases prior to 4.2.16.Final
Netty's HTTP CORS handler silently rewrites the Vary response header to Vary: Origin in releases before 4.1.137.Final an
Denial of service in the Netty HTTP/3 codec (io.netty:netty-codec-http3) prior to version 4.2.15.Final allows remote una
Exploit-DB