Critical · published August 30, 2025
⚠️ Eventlet's HTTP WSGI parser has a sneaky flaw lurking in its trailer handling! Before version 0.40.3, it’s like trying to sneak a side dish into a meal without the chef noticing. 🍽️ Think of it like a restaurant where a waiter accepts orders without checking for allergies — a dangerous oversight! In this case, attackers can smuggle malicious requests under the radar, bypassing security measures and causing chaos for unsuspecting diners and staff. If exploited, this vulnerability could allow attackers to sidestep front-end security, strike at active site users, and even poison web caches. The ripple effects could lead to compromised private data and a seriously tarnished reputation. Yikes!
Think of it like a restaurant where a waiter accepts orders without checking for allergies — a dangerous oversight! In this case, attackers can smuggle malicious requests under the radar, bypassing security measures and causing chaos for unsuspecting diners and staff. This HTTP Request Smuggling vulnerability arises from Eventlet's improper handling of HTTP trailer sections, allowing crafted requests to bypass security controls. As a result, attackers can manipulate how requests are processed by the server, potentially leading to unauthorized access or data corruption.
If exploited, this vulnerability could allow attackers to sidestep front-end security, strike at active site users, and even poison web caches. The ripple effects could lead to compromised private data and a seriously tarnished reputation. Yikes! Update Eventlet to version 0.40.3 immediately to patch this vulnerability. As a temporary workaround, avoid using eventlet.wsgi in front of untrusted clients. Audit your configurations to ensure trailers are not required if you're behind an eventlet.wsgi proxy. This is fixable! Follow these steps, and you’ll have your security tightened up in no time. 🛡️
| Product | Versions | Fixed in |
|---|---|---|
| eventlet/eventlet | < 0.40.3 | 0.40.3 |