Описание
Undici has Unhandled Exception in WebSocket Client Due to Invalid server_max_window_bits Validation
Impact
The undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range server_max_window_bits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.
The vulnerability exists because:
- The
isValidClientWindowBits()function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15 - The
createInflateRaw()call is not wrapped in a try-catch block - The resulting exception propagates up through the call stack and crashes the Node.js process
Patches
Has the problem been patched? What versions should users upgrade to?
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
Ссылки
- https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8
- https://nvd.nist.gov/vuln/detail/CVE-2026-2229
- https://hackerone.com/reports/3487486
- https://cna.openjsf.org/security-advisories.html
- https://datatracker.ietf.org/doc/html/rfc7692
- https://nodejs.org/api/zlib.html#class-zlibinflateraw
Пакеты
undici
< 6.24.0
6.24.0
undici
>= 7.0.0, < 7.24.0
7.24.0
Связанные уязвимости
ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range server_max_window_bits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination. The vulnerability exists because: * The isValidClientWindowBits() function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15 * The createInflateRaw() call is not wrapped in a try-catch block * The resulting exception propagates up through the call stack and crashe...
A flaw was found in the undici WebSocket client. A remote malicious server can exploit this vulnerability by sending a WebSocket frame with an invalid `server_max_window_bits` parameter within the permessage-deflate extension. This improper validation causes the client's Node.js process to terminate, leading to a denial-of-service (DoS) condition for the client.
ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range server_max_window_bits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination. The vulnerability exists because: * The isValidClientWindowBits() function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15 * The createInflateRaw() call is not wrapped in a try-catch block * The resulting exception propagates up through the call stack and c
ImpactThe undici WebSocket client is vulnerable to a denial-of-service ...