BlackTreeIndependent security intelligence
← Back to the CVE catalogue
Full vulnerability report · 2023
CVE-2023-35945High confidence

Envoy vulnerable to HTTP/2 memory leak in nghttp2 codec

envoyproxy · envoy

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

3 current
SEVD-2025-189-03 · CSAF 2.0 · revision 2.0.0 · finalSchneider Electric CPCERTEcoStruxure™ Power Operation
2 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • EcoStruxure™ Power Operation (EPO) 2022 CU6 and prior
  • EcoStruxure™ Power Operation (EPO) 2024 CU1 and prior
Summary
Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy's HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.
Remediation
The CVE's listed above affect the PostgresSQL pgadmin tool. If you have installed this tool, not required by EcoStruxure™ Power Operation 2024, we recommend you uninstall it from your EPO server and client machines.We strongly recommend customers take the following actions:• If waveform analysis and ETAP simulation features are not used, uninstall PostgreSQLOR• For those customers using waveform analysis and ETAP simulation features, we recommend all deployments of EPO only accept connections from localhost in PostgresSQL. Contact customer care for information on how to modify PostgreSQL. Further, we recommend you manually uninstall PostgreSQL 14.10 and update to PostgreSQL 14.17 or higher. EcoStruxure™ Power Operation 2024 CU2 includes an updated version of PostgreSQL and is available for download here: https://community.se.com/t5/EcoStruxure-Power-Operation/v2024-Release-amp-Updates-Install-Procedure/m-p/478928/thread-id/6997#M6997
SSA-398330 · CSAF 2.0 · revision 18 · interimSiemens ProductCERTSSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5
5 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)
Summary
Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.
Remediation
Update to V3.1.5 or later version
SSA-943925 · CSAF 2.0 · revision 2 · interimSiemens ProductCERTSSA-943925: Multiple Vulnerabilities in SINEC NMS before V2.0 SP1
1 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SINEC NMS
Summary
Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.
Remediation
Update to V2.0 SP1 or later version
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2023-39929

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.

What

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.

Likely attack path
a network path → Uncontrolled Resource Consumption → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-400 ↗

CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-400Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2023-2058Red Hat OpenShift Service Mesh und Service Mesh Containers: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat OpenShift Service Mesh und Service Mesh Containers, sowie Red Hat Enterprise Linux ausnutzen, um einen Denial of Service Zustand herbeizuführen, Dateien zu manipulieren, Sicherheitsvorkehrungen zu umgehen oder Informationen offenzulegen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0969Multiples vulnérabilités dans les produits VMware

Record?id=CVE-2023-3428 Référence CVE CVE-2023-3446 https://www.cve.org/CVERecord?id=CVE-2023-3446 Référence CVE CVE-2023-34474 https://www.cve.org/CVERecord?id=CVE-2023-34474 Référence CVE CVE-2023-34475 https://www.cve.org/CVERecord?id=CVE-2023-34475 Référence CVE CVE-2023-34967 https://www.cve.org/CVERecord?id=CVE-2023-34967 Référence CVE CVE-2023-34968 https://www.cve.org/CVERecord?id=CVE-2023-34968 Référence CVE CVE-2023-34969 https://www.cve.org/CVERecord?id=CVE-2023-34969 Référence CVE CVE-2023-35116 https://www.cve.org/CVERecord?id=CVE-2023-35116 Référence CVE CVE-2023-3576 https://www.cve.org/CVERecord?id=CVE-2023-3576 Référence CVE CVE-2023-35945 https://www.cve.org/CVERecord?id=CVE-2023-35945 Référence CVE CVE-2023-36054 https://www.cve.org/CVERecord?id=CVE-2023-36054 Référence CVE CVE-2023-3618 https://www.cve.org/CVERecord?id=CVE-2023-3618 Référence CVE CVE-2023-36632 https://www.cve.org/CVERecord?id=CVE-2023-36632 Référence CVE CVE-2023-37769 https://www.cve.org/CVERecord?id=CVE-2023-37769 Référence CVE CVE-2023-38037 https://www.cve.org/CVERecord?id=CVE-2023-38037 Référence CVE CVE-2023-38039 https://www.cve.org/CVERecord?id=CVE-2023-38039 Référence CVE CVE-2023-3817 https://www.cve.org/CVERecord?id=CVE-2023-3817 Référence CVE CVE-2023-38469 https://www.cve.org/CVERecord?id=CVE-

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0565Multiples vulnérabilités dans les produits Schneider Electric

De multiples vulnérabilités ont été découvertes dans les produits Schneider Electric. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un déni de service à distance.

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0156Multiples vulnérabilités dans les produits Tenable

d?id=CVE-2023-30624 Référence CVE CVE-2023-31124 https://www.cve.org/CVERecord?id=CVE-2023-31124 Référence CVE CVE-2023-31130 https://www.cve.org/CVERecord?id=CVE-2023-31130 Référence CVE CVE-2023-31147 https://www.cve.org/CVERecord?id=CVE-2023-31147 Référence CVE CVE-2023-32067 https://www.cve.org/CVERecord?id=CVE-2023-32067 Référence CVE CVE-2023-35941 https://www.cve.org/CVERecord?id=CVE-2023-35941 Référence CVE CVE-2023-35942 https://www.cve.org/CVERecord?id=CVE-2023-35942 Référence CVE CVE-2023-35943 https://www.cve.org/CVERecord?id=CVE-2023-35943 Référence CVE CVE-2023-35944 https://www.cve.org/CVERecord?id=CVE-2023-35944 Référence CVE CVE-2023-35945 https://www.cve.org/CVERecord?id=CVE-2023-35945 Référence CVE CVE-2023-44487 https://www.cve.org/CVERecord?id=CVE-2023-44487 Référence CVE CVE-2024-0057 https://www.cve.org/CVERecord?id=CVE-2024-0057 Référence CVE CVE-2024-1683 https://www.cve.org/CVERecord?id=CVE-2024-1683 Référence CVE CVE-2024-20672 https://www.cve.org/CVERecord?id=CVE-2024-20672 Référence CVE CVE-2024-23322 https://www.cve.org/CVERecord?id=CVE-2024-23322 Référence CVE CVE-2024-23323 https://www.cve.org/CVERecord?id=CVE-2024-23323 Référence CVE CVE-2024-23324 https://www.cve.org/CVERecord?id=CVE-2024-23324 Référence CVE CVE-2024-23325 https://www.cve.org/CVERecord?id=CVE-

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0119Multiples vulnérabilités dans les produits Siemens

rd?id=CVE-2023-3446 Référence CVE CVE-2023-34872 https://www.cve.org/CVERecord?id=CVE-2023-34872 Référence CVE CVE-2023-34969 https://www.cve.org/CVERecord?id=CVE-2023-34969 Référence CVE CVE-2023-35001 https://www.cve.org/CVERecord?id=CVE-2023-35001 Référence CVE CVE-2023-35788 https://www.cve.org/CVERecord?id=CVE-2023-35788 Référence CVE CVE-2023-35789 https://www.cve.org/CVERecord?id=CVE-2023-35789 Référence CVE CVE-2023-35823 https://www.cve.org/CVERecord?id=CVE-2023-35823 Référence CVE CVE-2023-35824 https://www.cve.org/CVERecord?id=CVE-2023-35824 Référence CVE CVE-2023-35828 https://www.cve.org/CVERecord?id=CVE-2023-35828 Référence CVE CVE-2023-35945 https://www.cve.org/CVERecord?id=CVE-2023-35945 Référence CVE CVE-2023-36054 https://www.cve.org/CVERecord?id=CVE-2023-36054 Référence CVE CVE-2023-3611 https://www.cve.org/CVERecord?id=CVE-2023-3611 Référence CVE CVE-2023-36617 https://www.cve.org/CVERecord?id=CVE-2023-36617 Référence CVE CVE-2023-36664 https://www.cve.org/CVERecord?id=CVE-2023-36664 Référence CVE CVE-2023-3776 https://www.cve.org/CVERecord?id=CVE-2023-3776 Référence CVE CVE-2023-37920 https://www.cve.org/CVERecord?id=CVE-2023-37920 Référence CVE CVE-2023-38039 https://www.cve.org/CVERecord?id=CVE-2023-38039 Référence CVE CVE-2023-3817 https://www.cve.org/CVERecord?id=CVE-2

Official advisory
CERT-FR · French · CERTFR-2023-AVI-1015Multiples vulnérabilités dans les produits Siemens

cord?id=CVE-2023-3212 Référence CVE CVE-2023-32611 https://www.cve.org/CVERecord?id=CVE-2023-32611 Référence CVE CVE-2023-32636 https://www.cve.org/CVERecord?id=CVE-2023-32636 Référence CVE CVE-2023-32643 https://www.cve.org/CVERecord?id=CVE-2023-32643 Référence CVE CVE-2023-32665 https://www.cve.org/CVERecord?id=CVE-2023-32665 Référence CVE CVE-2023-34319 https://www.cve.org/CVERecord?id=CVE-2023-34319 Référence CVE CVE-2023-3446 https://www.cve.org/CVERecord?id=CVE-2023-3446 Référence CVE CVE-2023-34969 https://www.cve.org/CVERecord?id=CVE-2023-34969 Référence CVE CVE-2023-35001 https://www.cve.org/CVERecord?id=CVE-2023-35001 Référence CVE CVE-2023-35945 https://www.cve.org/CVERecord?id=CVE-2023-35945 Référence CVE CVE-2023-3609 https://www.cve.org/CVERecord?id=CVE-2023-3609 Référence CVE CVE-2023-3611 https://www.cve.org/CVERecord?id=CVE-2023-3611 Référence CVE CVE-2023-3772 https://www.cve.org/CVERecord?id=CVE-2023-3772 Référence CVE CVE-2023-3817 https://www.cve.org/CVERecord?id=CVE-2023-3817 Référence CVE CVE-2023-38380 https://www.cve.org/CVERecord?id=CVE-2023-38380 Référence CVE CVE-2023-38408 https://www.cve.org/CVERecord?id=CVE-2023-38408 Référence CVE CVE-2023-38545 https://www.cve.org/CVERecord?id=CVE-2023-38545 Référence CVE CVE-2023-38546 https://www.cve.org/CVERecord?id=CVE-2023

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
EcoStruxure™ Power Operation (EPO) 2022 CU6 and prior; EcoStruxure™ Power Operation (EPO) 2024 CU1 and prior
Fixed
EcoStruxure™ Power Operation 2024 CU2; EcoStruxure™ Power Operation 2022 CU7
Action
The CVE's listed above affect the PostgresSQL pgadmin tool. If you have installed this tool, not required by EcoStruxure™ Power Operation 2024, we recommend you uninstall it from your EPO server and client machines.We strongly recommend customers take the following actions:• If waveform analysis and ETAP simulation features are not used, uninstall PostgreSQLOR• For those customers using waveform analysis and ETAP simulation features, we recommend all deployments of EPO only accept connections from localhost in PostgresSQL. Contact customer care for information on how to modify PostgreSQL. Further, we recommend you manually uninstall PostgreSQL 14.10 and update to PostgreSQL 14.17 or higher. EcoStruxure™ Power Operation 2024 CU2 includes an updated version of PostgreSQL and is available for download here: https://community.se.com/t5/EcoStruxure-Power-Operation/v2024-Release-amp-Updates-Install-Procedure/m-p/478928/thread-id/6997#M6997
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 13 Jul 2023 · Last source change 31 Oct 2024, 16:24 UTC · CWE-400 · Uncontrolled Resource Consumption

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2023-39929
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2023-39929↗Vendor CSAF · Schneider Electric CPCERT↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2023-35945 · cve.blacktree.nl