### [CVE-2024-30255](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-30255)
![](https://img.shields.io/static/v1?label=Product&message=envoy&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3D%20%3E%3D%201.29.0%2C%20%3C%201.29.3%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-390%3A%20Detection%20of%20Error%20Condition%20Without%20Action&color=brighgreen)

### Description

Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustion due to flood of CONTINUATION frames. Envoy's HTTP/2 codec allows the client to send an unlimited number of CONTINUATION frames even after exceeding Envoy's header map limits. This allows an attacker to send a sequence of CONTINUATION frames without the END_HEADERS bit set causing CPU utilization, consuming approximately 1 core per 300Mbit/s of traffic and culminating in denial of service through CPU exhaustion. Users should upgrade to version 1.29.3, 1.28.2, 1.27.4, or 1.26.8 to mitigate the effects of the CONTINUATION flood. As a workaround, disable HTTP/2 protocol for downstream connections.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/Ampferl/poc_http2-continuation-flood
- https://github.com/DrewskyDev/H2Flood
- https://github.com/Vos68/HTTP2-Continuation-Flood-PoC
- https://github.com/blackmagic2023/Envoy-CPU-Exhaustion-Vulnerability-PoC
- https://github.com/lockness-Ko/CVE-2024-27316
- https://github.com/nomi-sec/PoC-in-GitHub