Vulnerability Information
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Vulnerability Title
uTLS ServerHellos are accepted without checking TLS 1.3 downgrade canaries
Vulnerability Description
uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. In versions 1.6.7 and below, uTLS did not implement the TLS 1.3 downgrade protection mechanism specified in RFC 8446 Section 4.1.3 when using a uTLS ClientHello spec. This allowed an active network adversary to downgrade TLS 1.3 connections initiated by a uTLS client to a lower TLS version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension, causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello random field). Because uTLS did not check the downgrade canary in the ServerHello random field, clients would accept the downgraded connection without detecting the attack. This attack could also be used by an active network attacker to fingerprint uTLS connections. This issue has been fixed in version 1.7.0.
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Vulnerability Type
保护机制失效
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 1.6.7及之前版本存在安全漏洞，该漏洞源于未实现TLS 1.3降级保护机制，可能导致连接降级攻击。
CVSS Information
N/A
Vulnerability Type
N/A