TI-2024-15426 Aliases CVE-2024-23324

Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata

MEDIUM 44CWE-20Published 2024-02-09 · Updated 2024-08-19

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · None · None
Fix status: Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

Envoy is a high-performance edge/middle/service proxy. External authentication can be bypassed by downstream connections. Downstream clients can force invalid gRPC requests to be sent to ext_authz, circumventing ext_authz checks when failure_mode_allow is set to true. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.006 48th percentileScored 2026-11-07

Fix Partial envoy (envoyproxy): 1.29.1, 1.28.1, 1.27.3 +1Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
envoyproxy	envoy	1.29.0 to before 1.29.1; 1.28.0 to before 1.28.1; 1.27.0 to before 1.27.3; before 1.26.7	1.29.1, 1.28.1, 1.27.3, 1.26.7	Patch available	CNA

envoy Vendorenvoyproxy Affected 1.29.0 to before 1.29.1; 1.28.0 to before 1.28.1; 1.27.0 to before 1.27.3; before 1.26.7 Fixed in 1.29.1, 1.28.1, 1.27.3, 1.26.7 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:envoyproxy:envoy::::::::	1.26.0 to before 1.26.7; 1.27.0 to before 1.27.3; 1.28.0 to before 1.28.1; 1.29.0 to before 1.29.1	Vulnerable	envoyproxy

cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions 1.26.0 to before 1.26.7; 1.27.0 to before 1.27.3; 1.28.0 to before 1.28.1; 1.29.0 to before 1.29.1 Vulnerable ·envoyproxy

Remediation

Fix · CNA envoy (envoyproxy) Fixed in 1.29.1, 1.28.1, 1.27.3, 1.26.7

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
OpenShift Service Mesh 2	Affected	No fix yet

Timeline

2026-10-02 Threatist record created from CVE-2024-23324

References

Patch 1

https://github.com/envoyproxy/envoy/commit/29989f6cc8bfd8cd2ffcb7c42711eb02c7a5168a

Advisory 1

https://github.com/envoyproxy/envoy/security/advisories/GHSA-gq3v-vvhj-96j6

TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
TI-2024-20001 HTTP/2: CPU exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
TI-2024-18524 HTTP/2: memory exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
TI-2023-12215 Envoy client may fake the header `x-envoy-original-path` CVSS 3.1CRITICAL 9.1
TI-2023-18002 Envoy vulnerable to OAuth2 credentials exploit with permanent validity CVSS 3.1CRITICAL 9.8

See all 126 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences