ReDoS Vulnerability in Anthropic's MCP TypeScript SDK - @modelcontextprotocol/sdk
Summary
GHSA-8r9q-7v3j-jr4g: Anthropic's MCP TypeScript SDK has a ReDoS vulnerability. Affects @modelcontextprotocol/sdk versions < 1.25.1. No fix is published. How to fix ↓
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Background
The @modelcontextprotocol/sdk is a TypeScript SDK developed by Anthropic, designed to facilitate interactions with the Model Context Protocol (MCP). This SDK allows developers to build applications that can effectively communicate with various AI models. It is widely used for its ease of integration and robust functionality. However, versions up to and including 1.25.1 are vulnerable to a ReDoS attack, which can severely impact application performance.
Vulnerability Detail
Anthropic's MCP TypeScript SDK versions up to and including 1.25.1 contain a regular expression denial of service (ReDoS) vulnerability in the UriTemplate class. This vulnerability arises from the use of nested quantifiers in a dynamically generated regular expression during URI matching. When processing RFC 6570 exploded array patterns, specially crafted inputs can trigger catastrophic backtracking, leading to excessive CPU consumption. An attacker can exploit this vulnerability by supplying a malicious URI, causing the Node.js process to become unresponsive and resulting in a denial of service.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, you can implement input validation to sanitize URIs before processing them with the SDK. This can help mitigate the risk of triggering the ReDoS vulnerability. For example, you can use a simple regex to validate the structure of the URI before passing it to the UriTemplate class.
Conclusion
The ReDoS vulnerability in Anthropic's MCP TypeScript SDK poses a significant risk to applications using affected versions. It is crucial to update to the latest version to mitigate this risk. Additionally, implementing input validation can serve as a temporary workaround while transitioning to the patched version.
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FAQ
A ReDoS (Regular Expression Denial of Service) vulnerability occurs when a regular expression takes an excessive amount of time to evaluate, often due to nested quantifiers, leading to denial of service.
An attacker can exploit this vulnerability by sending specially crafted URIs, causing your application to become unresponsive and leading to a denial of service.
The vulnerability affects all versions of the @modelcontextprotocol/sdk up to and including 1.25.1.
Yes, a patched version (1.25.2 and later) is available. It is recommended to update to this version to mitigate the vulnerability.
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