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TI-2023-12220 Aliases CVE-2023-27492

Envoy may crash when a large request body is processed in Lua filter

Priority MEDIUM 62CWE-770Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-770.

Summary

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the Lua filter is vulnerable to denial of service. Attackers can send large request bodies for routes that have Lua filter enabled and trigger crashes. As of versions versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy no longer invokes the Lua coroutine if the filter has been reset. As a workaround for those whose Lua filter is buffering all requests/ responses, mitigate by using the buffer filter to avoid triggering the local reply in the Lua filter.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00686 52nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial envoy (envoyproxy): 1.25.3, 1.24.4, 1.23.6 +1Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
envoyproxyenvoy1.25.0 to before 1.25.3; 1.24.0 to before 1.24.4; 1.23.0 to before 1.23.6; before 1.22.91.25.3, 1.24.4, 1.23.6, 1.22.9Patch availableCNA
  • envoy Vendorenvoyproxy Affected 1.25.0 to before 1.25.3; 1.24.0 to before 1.24.4; 1.23.0 to before 1.23.6; before 1.22.9 Fixed in 1.25.3, 1.24.4, 1.23.6, 1.22.9 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*before 1.22.9; 1.23.0 to before 1.23.6; 1.24.0 to before 1.24.4; 1.25.0 to before 1.25.3Vulnerableenvoyproxy
  • cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions before 1.22.9; 1.23.0 to before 1.23.6; 1.24.0 to before 1.24.4; 1.25.0 to before 1.25.3 Vulnerable ·envoyproxy

Remediation

  • Fix · CNA envoy (envoyproxy) Fixed in 1.25.3, 1.24.4, 1.23.6, 1.22.9

Red Hat 1 advisory

  • RHSA-2023:4623 Released 2023-08-11 · Red Hat rating Important
    Red Hat OpenShift Service Mesh 2.2.9 security update
    • RHOSSM 2.2 for RHEL 8 openshift-service-mesh/proxyv2-rhel8

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
OpenShift Service Mesh 2.1AffectedNo fix planned: Will not fix
RHOSSM 2.2 for RHEL 8Fixed RHSA-2023:4623
Not affected: 1 product
  • RHOSSM 2.2 for RHEL 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-27492

References

Exploit 1

  • 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