CVE-2024-23324

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

HIGH

7.5

CVSS Score

Published: February 9, 2024 at 10:48 PM UTC

Updated: June 17, 2026 at 07:12 AM UTC

1 product affected across 1 vendorEnvoy

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Severity

HIGH7.5

Exploit prediction

EPSS 0.6%

SSVC

No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Envoy · Envoyproxy

95%

v < 1.26.7v < 1.27.3v < 1.28.1v < 1.29.11.26.0 ≤ v < 1.26.71.27.0 ≤ v < 1.27.31.28.0 ≤ v < 1.28.11.29.0 ≤ v < 1.29.11.27.0 1.28.0 1.29.0

Affected range stops below 1.26.7, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.27.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.28.1, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.29.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

x_refsource_MISCPatchVendor Advisory

Source: [email protected]

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

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

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

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: HIGH
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-20NVD-CWE-noinfo

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