Vulnerability Information
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Vulnerability Title
uTLS has a Chrome Parrot Fingerprint Vulnerability due to GREASE ECH Cipher Suite Mismatch
Vulnerability Description
uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. Versions 1.6.0 through 1.8.0 contain a fingerprint mismatch with Chrome when using GREASE ECH, related to cipher suite selection. When Chrome selects the preferred cipher suite in the outer ClientHello and for ECH, it does so consistently based on hardware support—for example, if it prefers AES for the outer cipher suite, it also uses AES for ECH. However, the Chrome parrot in uTLS hardcodes AES preference for outer cipher suites but selects the ECH cipher suite randomly between AES and ChaCha20. This creates a 50% chance of selecting ChaCha20 for ECH while using AES for the outer cipher suite, a combination impossible in Chrome. This issue only affects GREASE ECH; in real ECH, Chrome selects the first valid cipher suite when AES is preferred, which uTLS handles correctly. This issue has been fixed in version 1.8.1.
CVSS Information
N/A
Vulnerability Type
CWE-1240
Vulnerability Title
uTLS 安全漏洞
Vulnerability Description
uTLS是Refraction Networking开源的一个Go语言代码库。 uTLS 1.6.0版本至1.8.0版本存在安全漏洞，该漏洞源于使用GREASE ECH时密码套件选择逻辑不一致，可能导致指纹不匹配。
CVSS Information
N/A
Vulnerability Type
N/A