CVE-2024-32475

Envoy RELEASE_ASSERT using auto_sni with :authority header > 255 bytes

HIGH

7.5

CVSS Score

Published: April 18, 2024 at 02:18 PM UTC

Updated: June 17, 2026 at 07:29 AM UTC

1 product affected across 1 vendorEnvoy

Using envoy by envoyproxy?

Get instant alerts when new vulnerabilities affect envoy - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH7.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

Description

Envoy is a cloud-native, open source edge and service proxy. When an upstream TLS cluster is used with `auto_sni` enabled, a request containing a `host`/`:authority` header longer than 255 characters triggers an abnormal termination of Envoy process. Envoy does not gracefully handle an error when setting SNI for outbound TLS connection. The error can occur when Envoy attempts to use the `host`/`:authority` header value longer than 255 characters as SNI for outbound TLS connection. SNI length is limited to 255 characters per the standard. Envoy always expects this operation to succeed and abnormally aborts the process when it fails. This vulnerability is fixed in 1.30.1, 1.29.4, 1.28.3, and 1.27.5.

Affected

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

Envoy · Envoyproxy

95%

v < 1.27.5v < 1.28.3v < 1.29.4v < 11.30.11.13.0 ≤ v < 1.27.51.28.0 ≤ v < 1.28.31.29.0 ≤ v < 1.29.41.13.0 1.30.0

Affected range stops below 1.27.5, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.28.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.29.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 11.30.1, 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_MISCPatch

Source: [email protected]

https://github.com/envoyproxy/envoy/commit/b47fc6648d7c2dfe0093a601d44cb704b7bad382

x_refsource_CONFIRMPatchVendor Advisory

Source: [email protected]

https://github.com/envoyproxy/envoy/security/advisories/GHSA-3mh5-6q8v-25wj

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

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

CVSS

7.5HIGHGitHub_M

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

Vector?

Quick Info

StatusANALYZED

CWE

CWE-253CWE-617

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create account Sign in

Free plan, no card