Advisories for Pypi/Fschat package

2025

FastChat Uncontrolled Resource Consumption vulnerability

In lm-sys/fastchat Release v0.2.36, the server fails to handle excessive characters appended to the end of multipart boundaries. This flaw can be exploited by sending malformed multipart requests with arbitrary characters at the end of the boundary. Each extra character is processed in an infinite loop, leading to excessive resource consumption and a complete denial of service (DoS) for all users. The vulnerability is unauthenticated, meaning no user login or …

FastChat Server-Side Request Forgery vulnerability

A Server-Side Request Forgery (SSRF) vulnerability was identified in the lm-sys/fastchat web server, specifically in the affected version git 2c68a13. This vulnerability allows an attacker to access internal server resources and data that are otherwise inaccessible, such as AWS metadata credentials.

FastChat Server-Side Request Forgery vulnerability

A Server-Side Request Forgery (SSRF) vulnerability exists in lm-sys/fastchat version 0.2.36. The vulnerability is present in the /queue/join? endpoint, where insufficient validation of the path parameter allows an attacker to send crafted requests. This can lead to unauthorized access to internal networks or the AWS metadata endpoint, potentially exposing sensitive data and compromising internal servers.

FastChat open redirect vulnerability

An open redirect vulnerability in lm-sys/fastchat Release v0.2.36 allows a remote unauthenticated attacker to redirect users to arbitrary websites via a specially crafted URL. This can be exploited for phishing attacks, malware distribution, and credential theft.

FastChat Denial of Service vulnerability

A Denial of Service (DoS) vulnerability exists in the file upload feature of lm-sys/fastchat version 0.2.36. The vulnerability is due to improper handling of form-data with a large filename in the file upload request. An attacker can exploit this by sending a payload with an excessively large filename, causing the server to become overwhelmed and unavailable to legitimate users.