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Full vulnerability report · 2022
CVE-2022-41556High confidence

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients

n/a · n/a

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.

1 current
SSA-806742 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-806742: Multiple Vulnerabilities in SCALANCE XCM-/XRM-300 before V2.4
11 known affected

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

  • SCALANCE XCH328 (6GK5328-4TS01-2EC2)
  • SCALANCE XCM324 (6GK5324-8TS01-2AC2)
  • SCALANCE XCM328 (6GK5328-4TS01-2AC2)
  • SCALANCE XCM332 (6GK5332-0GA01-2AC2)
  • SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3)
  • SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3)
  • SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3)
  • SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3)
  • SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3)
  • SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3)
  • SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3)
Summary
A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.
Remediation
Update to V2.4 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-2022-44748

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

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

What

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

Why

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

Why

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Missing Release of Memory after Effective Lifetime → 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-401 ↗

CWE-401: Missing Release of Memory after Effective Lifetime. The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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-401Public 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-2023-0561Xerox FreeFlow Print Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um die Vertraulichkeit, Verfügbarkeit und Integrität des Systems zu gefährden.

Official advisory
BSI · German · WID-SEC-W-2022-1585lighttpd: Schwachstelle ermöglicht Denial of Service

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in lighttpd ausnutzen, um einen Denial of Service Angriff durchzuführen.

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

d?id=CVE-2022-36227 Référence CVE CVE-2022-36760 https://www.cve.org/CVERecord?id=CVE-2022-36760 Référence CVE CVE-2022-37436 https://www.cve.org/CVERecord?id=CVE-2022-37436 Référence CVE CVE-2022-37454 https://www.cve.org/CVERecord?id=CVE-2022-37454 Référence CVE CVE-2022-37797 https://www.cve.org/CVERecord?id=CVE-2022-37797 Référence CVE CVE-2022-38725 https://www.cve.org/CVERecord?id=CVE-2022-38725 Référence CVE CVE-2022-39189 https://www.cve.org/CVERecord?id=CVE-2022-39189 Référence CVE CVE-2022-39260 https://www.cve.org/CVERecord?id=CVE-2022-39260 Référence CVE CVE-2022-41409 https://www.cve.org/CVERecord?id=CVE-2022-41409 Référence CVE CVE-2022-41556 https://www.cve.org/CVERecord?id=CVE-2022-41556 Référence CVE CVE-2022-41715 https://www.cve.org/CVERecord?id=CVE-2022-41715 Référence CVE CVE-2022-41717 https://www.cve.org/CVERecord?id=CVE-2022-41717 Référence CVE CVE-2022-41723 https://www.cve.org/CVERecord?id=CVE-2022-41723 Référence CVE CVE-2022-41860 https://www.cve.org/CVERecord?id=CVE-2022-41860 Référence CVE CVE-2022-41861 https://www.cve.org/CVERecord?id=CVE-2022-41861 Référence CVE CVE-2022-41862 https://www.cve.org/CVERecord?id=CVE-2022-41862 Référence CVE CVE-2022-41903 https://www.cve.org/CVERecord?id=CVE-2022-41903 Référence CVE CVE-2022-4203 https://www.cve.org/CVERecord?id=C

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
SCALANCE XCH328 (6GK5328-4TS01-2EC2); SCALANCE XCM324 (6GK5324-8TS01-2AC2); SCALANCE XCM328 (6GK5328-4TS01-2AC2); SCALANCE XCM332 (6GK5332-0GA01-2AC2); SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3); SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3); SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3); SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3); SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3); SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3); SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3)
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Update to V2.4 or later version
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 6 Oct 2022 · Last source change 3 Aug 2024, 12:42 UTC · CWE-401 · Missing Release of Memory after Effective Lifetime

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
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-2022-44748
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceNIST NVD
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
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2022-44748↗Vendor CSAF · Siemens ProductCERT↗CVE authority or vendor reference↗Public exploit 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-2022-41556 · cve.blacktree.nl