GHSA-rj35-4m94-77jh

Suggest an improvement
Source
https://github.com/advisories/GHSA-rj35-4m94-77jh
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-rj35-4m94-77jh/GHSA-rj35-4m94-77jh.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-rj35-4m94-77jh
Aliases
Published
2025-12-05T18:12:51Z
Modified
2025-12-10T20:19:27.162055Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Envoy forwards early CONNECT data in TCP proxy mode
Details

Summary

Forwarding of early CONNECT data in TCP proxy mode.

Details

Per RFC 7231-4.3.6 the sender of CONNECT (and all inbound proxies) switch to tunnel mode only after receiving 2xx response. However in TCP proxy mode, Envoy accepts client data before it has issued a 2xx response and eagerly proxies it to an established TCP connection. This creates possibility of a de-synchronized tunnel state if a proxy upstream from Envoy responds with a status other an 2xx.

The RFC does not specify the behavior in case an early CONNECT data is received and early CONNECT data is common as a latency reduction mechanism. To prevent disruption to existing deployments Envoy will by default allow early CONNECT data. Setting the envoy.reloadable_features.reject_early_connect_data runtime flag to true will cause CONNECT requests that send data before 2xx response to be rejected. This options should be enabled if there are intermediaries upstream from Envoy that may reject establishment of a CONNECT tunnel.

Impact

De-synchronization of CONNECT tunnel state if a forwarding proxy upstream from Envoy responds with a non 2xx status.

Attack vector(s)

Sending data for a CONNECT request before receiving 2xx response.

Patches

Users should upgrade to v1.36.3, v1.35.7, v1.34.11 or v1.33.13

Credits

chasingimpact (Patrick)

Database specific 
{
    "cwe_ids": [
        "CWE-693"
    ],
    "github_reviewed_at": "2025-12-05T18:12:51Z",
    "severity": "LOW",
    "nvd_published_at": "2025-12-03T18:15:47Z",
    "github_reviewed": true
}
References

Affected packages

Go

github.com/envoyproxy/envoy

Package

Name
github.com/envoyproxy/envoy
View open source insights on deps.dev
Purl
pkg:golang/github.com/envoyproxy/envoy

Affected ranges

Type
SEMVER
Events
Introduced
1.36.0
Fixed
1.36.3

Database specific

last_known_affected_version_range

"<= 1.36.2"

github.com/envoyproxy/envoy

Package

Name
github.com/envoyproxy/envoy
View open source insights on deps.dev
Purl
pkg:golang/github.com/envoyproxy/envoy

Affected ranges

Type
SEMVER
Events
Introduced
1.35.0
Fixed
1.35.7

Database specific

last_known_affected_version_range

"<= 1.35.6"

github.com/envoyproxy/envoy

Package

Name
github.com/envoyproxy/envoy
View open source insights on deps.dev
Purl
pkg:golang/github.com/envoyproxy/envoy

Affected ranges

Type
SEMVER
Events
Introduced
1.34.0
Fixed
1.34.11

Database specific

last_known_affected_version_range

"<= 1.34.10"

github.com/envoyproxy/envoy

Package

Name
github.com/envoyproxy/envoy
View open source insights on deps.dev
Purl
pkg:golang/github.com/envoyproxy/envoy

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.33.13

Database specific

last_known_affected_version_range

"<= 1.33.12"