CVE-2024-38477Network attack vector

Unauthenticated server crash via hostname-less proxy URI

Published Jul 1, 2024 · Updated Nov 3, 2025

NULL pointer dereference in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows remote attackers to crash the server. ap_proxy_determine_connection and ap_proxy_create_hdrbrgd accepted a parsed proxy URI without a hostname, then used the null hostname. The request must reach a mod_proxy configuration that processes the crafted hostname-less URI; the consequence is a server-process crash.

CVSS severity7.5
High
EPSS probability3.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows remote attackers to crash the server. ap_proxy_determine_connection and ap_proxy_create_hdrbrgd accepted a parsed proxy URI without a hostname, then used the null hostname. The request must reach a mod_proxy configuration that processes the crafted hostname-less URI; the consequence is a server-process crash.

The record

CVE
CVE-2024-38477
Published
Jul 1, 2024
Updated
Nov 3, 2025
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 1, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2.4.0 <=2.4.59

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=2.4.0 <=2.4.59

Published CVSS scores

7.5National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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