CVE-2024-29025: Netty HttpPostRequestDecoder can OOM
Summary The HttpPostRequestDecoder can be tricked to accumulate data. I have spotted currently two attack vectors
Details 1. While the decoder can store items on the disk if configured so, there are no limits to the number of fields the form can have, an attacher can send a chunked post consisting of many small fields that will be accumulated in the bodyListHttpData list. 2. The decoder cumulates bytes in the undecodedChunk buffer until it can decode a field, this field can cumulate data without limits
PoC
Here is a Netty branch that provides a fix + tests : https://github.com/vietj/netty/tree/post-request-decoder
Here is a reproducer with Vert.x (which uses this decoder) https://gist.github.com/vietj/f558b8ea81ec6505f1e9a6ca283c9ae3
Impact Any Netty based HTTP server that uses the HttpPostRequestDecoder to decode a form.
Other sources
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The HttpPostRequestDecoder can be tricked to accumulate data. While the decoder can store items on the disk if configured so, there are no limits to the number of fields the form can have, an attacher can send a chunked post consisting of many small fields that will be accumulated in the bodyListHttpData list. The decoder cumulates bytes in the undecodedChunk buffer until it can decode a field, this field can cumulate data without limits. This vulnerability is fixed in 4.1.108.Final.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-29025?
CVE-2024-29025 has a moderate severity rating due to its potential for denial of service through excessive data accumulation.
How do I fix CVE-2024-29025?
To address CVE-2024-29025, upgrade to version 4.1.108.Final of the io.netty:netty-codec-http package.
What are the affected software versions for CVE-2024-29025?
CVE-2024-29025 affects versions prior to 4.1.108.Final of io.netty:netty-codec-http as well as specific versions of IBM Cognos Analytics.
What types of attacks are associated with CVE-2024-29025?
CVE-2024-29025 can be exploited through denial of service attacks that leverage unlimited form field accumulations.
Is there a patch available for CVE-2024-29025?
Yes, patches are available for affected versions of IBM Cognos Analytics and recommended upgrades for io.netty:netty-codec-http.