Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2025-64763— Envoy forwards early CONNECT data in TCP proxy mode

Quick assessment

Affected
envoyproxy envoy
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Envoy是Enphase开源的一款用于连接智能家居设备的网关程序。 Envoy 1.33.12版本、1.34.10版本、1.35.6版本、1.36.2版本及之前版本存在安全漏洞，该漏洞源于TCP代理模式下处理CONNECT请求时存在状态不同步问题。

CVSS 3.7 · Low EPSS 0.30% · P21

Possible ATT&CK Techniques 1 AI

T1571 · Non-Standard Port
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2025-64763

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Envoy forwards early CONNECT data in TCP proxy mode
Source: CVE Program / CVE List V5
Vulnerability Description
Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
保护机制失效
Source: CVE Program / CVE List V5
Vulnerability Title
Envoy 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Envoy是Enphase开源的一款用于连接智能家居设备的网关程序。 Envoy 1.33.12版本、1.34.10版本、1.35.6版本、1.36.2版本及之前版本存在安全漏洞，该漏洞源于TCP代理模式下处理CONNECT请求时存在状态不同步问题。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
envoyproxy envoy >= 1.36.0, <= 1.36.2 -

II. Public POCs for CVE-2025-64763

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2025-64763

请登录查看更多情报信息。

Vendor Advisories for CVE-2025-64763 (1)

Same Patch Batch · envoyproxy · 2025-12-03 · 3 CVEs total

CVE-2025-64527 6.5 MEDIUM Envoy crashes when JWT authentication is configured with the remote JWKS fetching
CVE-2025-66220 5.0 MEDIUM Envoy’s TLS certificate matcher for `match_typed_subject_alt_names` may incorrectly treat

IV. Related Vulnerabilities

Same product: envoy
Same vendor: envoyproxy
Same weakness: CWE-693

V. Comments for CVE-2025-64763

No comments yet

Leave a comment