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Full vulnerability report · 2024
CVE-2024-36387High confidence

Apache HTTP Server: DoS by Null pointer in websocket over HTTP/2

Apache Software Foundation · Apache HTTP Server

5.4MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 1.71% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Apache Software Foundation Apache HTTP Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

8 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.60-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.60-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.60-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.60-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.61-1~deb12u1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.60-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.60-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiveapache2Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.2.4.58-1ubuntu8.2Canonical Ubuntu Security ↗Source updated 5 Oct 2026
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
CVE-2024-36387 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitymod_http2: DoS by null pointer in websocket over HTTP/2
19 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • jbcs-httpd24-mod_http2-0:2.0.29-3.el7jbcs.src as a component of Red Hat JBoss Core Services on RHEL 7 Server
  • jbcs-httpd24-mod_http2-0:2.0.29-3.el7jbcs.x86_64 as a component of Red Hat JBoss Core Services on RHEL 7 Server
  • jbcs-httpd24-mod_http2-debuginfo-0:2.0.29-3.el7jbcs.x86_64 as a component of Red Hat JBoss Core Services on RHEL 7 Server
  • jbcs-httpd24-mod_http2-0:2.0.29-3.el8jbcs.src as a component of Red Hat JBoss Core Services on RHEL 8
  • jbcs-httpd24-mod_http2-0:2.0.29-3.el8jbcs.x86_64 as a component of Red Hat JBoss Core Services on RHEL 8
  • jbcs-httpd24-mod_http2-debuginfo-0:2.0.29-3.el8jbcs.x86_64 as a component of Red Hat JBoss Core Services on RHEL 8
  • mod_http2-0:2.0.26-2.el9_4.1.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-2.el9_4.1.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-2.el9_4.1.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-2.el9_4.1.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-0:2.0.26-2.el9_4.1.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • mod_http2-debuginfo-0:2.0.26-2.el9_4.1.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
Summary
A flaw was found in the Apache HTTP Server. Serving WebSocket protocol upgrades over an HTTP/2 connection could result in a NULL pointer dereference, leading to a crash of the server process.
Remediation
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

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-2024-36338

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 actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

Serving WebSocket protocol upgrades over a HTTP/2 connection could result in a Null Pointer dereference, leading to a crash of the server process, degrading performance.

What

Serving WebSocket protocol upgrades over a HTTP/2 connection could result in a Null Pointer dereference, leading to a crash of the server process, degrading performance.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

Serving WebSocket protocol upgrades over a HTTP/2 connection could result in a Null Pointer dereference, leading to a crash of the server process, degrading performance.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. 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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → NULL Pointer Dereference → disrupt the affected service
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
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-476 ↗

CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.

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:L/UI:N/S:U/C:N/I:L/A:L

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.PRLowPrivileges required: The attacker needs basic user-level 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.ILowIntegrity impact: A successful attack can cause a limited loss.ALowAvailability impact: A successful attack can cause a limited 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.
NetworkDenial of serviceCWE-476
A

Official authority intelligence

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

BSI · German · WID-SEC-2024-1504Apache HTTP Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Apache HTTP Server ausnutzen, um beliebigen Code auszuführen, einen Denial-of-Service-Zustand herbeizuführen, Sicherheitsmaßnahmen zu umgehen oder vertrauliche Informationen offenzulegen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20240703Security Bulletin 03 Jul 2024

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 03 Jul 2024, published on 3 July 2024. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0676Multiples vulnérabilités dans Tenable Security Center

De multiples vulnérabilités ont été découvertes dans Tenable Security Center. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à la confidentialité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0533Multiples vulnérabilités dans Apache HTTP Server

De multiples vulnérabilités ont été découvertes dans Apache HTTP Server. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à la confidentialité des données.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2024-029329HTTP/2 WebSocketプロトコルアップグレードにおけるヌルポインタ参照によるサーバークラッシュの脆弱性

HTTP/2接続上でWebSocketプロトコルへのアップグレードを提供する際に、ヌルポインタ参照が発生し、サーバープロセスがクラッシュしたりパフォーマンスが低下したりする可能性があります。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2024-0275Kwetsbaarheden verholpen in Apache HHTP-server

Een kwaadwillende kan de kwetsbaarheden misbruiken om een Denial-of-Service te veroorzaken, middels een Server-Side-Request-Forgery (SSRF) verkeer te manipuleren, of om code uit te voeren binnen de webserver, waarvoor de kwaadwillende aanvankelijk niet is geautoriseerd.

Official advisory ↗
NCSC-NL · Dutch · NCSC-2024-0411Kwetsbaarheden verholpen in Oracle Database producten

Een kwaadwillende kan de kwetsbaarheden misbruiken om aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Manipuleren van data - Toegang tot gevoelige gegevens

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
Apache HTTP Server: 2.4.55 ≤ 2.4.59
Fixed
Action
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
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 1 Jul 2024 · Last source change 13 Feb 2025, 17:52 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.1
CVSS sourceCISA ADP
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-2024-36338
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

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

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    2.4.55 ≤ 2.4.59 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    2.4.55 ≤ 2.4.59 · Fixed: Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
    Red Hat Product Security ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2024-36338↗Red Hat Product Security security advisory↗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-2024-36387 · cve.blacktree.nl