CVE-2023-27492Public exploitNetwork attack vector

Proxy crash via resumed Lua coroutine

Published Apr 4, 2023 · Updated Feb 11, 2025

Denial of service in the Envoy Lua filter allows remote authenticated users to crash affected releases via a large request body. After an oversized buffered body triggers a local reply, the Lua filter resumes a coroutine whose objects have been destroyed, causing a segmentation fault when its asynchronous HTTP request returns. Exploitation requires a route with Lua enabled, a script that buffers the body and starts an HTTP request back through the filter, and timing that reaches the reset filter.

CVSS severity4.8
Medium
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Envoy Lua filter allows remote authenticated users to crash affected releases via a large request body. After an oversized buffered body triggers a local reply, the Lua filter resumes a coroutine whose objects have been destroyed, causing a segmentation fault when its asynchronous HTTP request returns. Exploitation requires a route with Lua enabled, a script that buffers the body and starts an HTTP request back through the filter, and timing that reaches the reset filter.

The record

CVE
CVE-2023-27492
Published
Apr 4, 2023
Updated
Feb 11, 2025
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-770, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 11, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.22.9
  2. Affected versionversion=>= 1.23.0, < 1.23.6
  3. Affected versionversion=>= 1.24.0, < 1.24.4
  4. Affected versionversion=>= 1.25.0, < 1.25.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Envoy Proxy · Envoyversion=< 1.22.9; version=>= 1.23.0, < 1.23.6; version=>= 1.24.0, < 1.24.4; version=>= 1.25.0, < 1.25.3

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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