CVE-2024-32475 | Envoy RELEASE_ASSERT using auto_sni with :authority header > 255 bytes

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.

Published: 2024-04-18 Last update: 2025-09-04 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-32475 is rated Moderate Risk (41.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-32475

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-24 0.19% 0.14% -0.05%
2 2026-05-07 0.14% 0.19% +0.05%
3 2025-11-16 — 0.14% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-32475

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-32475

OS Trackers for CVE-2024-32475

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2024-32475

Affected software / configurations for CVE-2024-32475

Vendor Product Version Raw CPE
envoyproxy envoy >= 1.13.0, < 1.27.5 cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy >= 1.28.0, < 1.28.3 cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy >= 1.29.0, < 1.29.4 cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy 1.30.0 cpe:2.3:a:envoyproxy:envoy:1.30.0:*:*:*:*:*:*:*

References for CVE-2024-32475

cvelogic Threat Intelligence