dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2024-42516

HIGH · 7.5 CVSS v3.1 Published 2025-07-10
Fix available
A fix is available. Upgrade to 2.4.64 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response. This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue. Users are recommended to upgrade to version 2.4.64, which fixes this issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

HTTP response splitting vulnerability in Apache HTTP Server core allows attackers who can manipulate Content-Type response headers to inject malicious content into HTTP responses, potentially leading to XSS, cache poisoning, or session hijacking. This is a re-emergence of CVE-2023-38709 where the original patch in version 2.4.59 was incomplete.

MitigationUpgrade Apache HTTP Server to version 2.4.64 which contains the complete fix for this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
HTTP ServerWeb server / proxy
Affected:>= 2.4.0, < 2.4.64

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine Apache HTTP Server version
    Run 'httpd -v' or 'apache2 -v' to retrieve the server version number from the ServerVersion string
    Affected if Version is 2.4.0 through 2.4.63 (inclusive)
  2. Check for mod_proxy and header manipulation modules
    Review loaded modules via 'httpd -M' or 'apache2ctl -M' and check configuration for mod_headers, mod_proxy, or any module that allows upstream header injection
    Affected if Modules that allow external manipulation of Content-Type headers are enabled and accessible to attackers
  3. Inspect reverse proxy or CGI configurations
    Examine Apache config files for ProxyPass, ProxyPassReverse, or CGI script setups that accept user input and could influence response headers
    Affected if Server acts as a reverse proxy or runs CGI scripts where untrusted input can affect Content-Type headers
  4. Verify Content-Type header handling
    Test if incoming requests can influence Content-Type response headers through query parameters, cookies, or request headers that get reflected in responses
    Affected if Application or module permits attacker-controlled input to set or modify Content-Type response headers

Server is affected if running Apache HTTP Server version 2.4.0 to 2.4.63 AND an attacker can manipulate Content-Type response headers via the application or server configuration.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.4.64 or later
Fixed in 2.4.64
Interim mitigation

Upgrade Apache HTTP Server to version 2.4.64 which contains the complete fix for this vulnerability.

Recommended fix High confidence

2.4.64

  1. Check current Apache HTTP Server version using 'httpd -v' or 'apache2 -v'
  2. Stop the Apache service using 'systemctl stop apache2' (Debian/Ubuntu) or 'systemctl stop httpd' (RHEL/CentOS)
  3. Download Apache HTTP Server 2.4.64 from the official Apache website (httpd.apache.org) or use your system's package manager if 2.4.64 is available
  4. If using source compilation: extract the tarball, run './configure', 'make', 'make install'
  5. If using package manager: run 'apt-get update && apt-get install apache2' (Debian/Ubuntu) or 'yum update httpd' (RHEL/CentOS)
  6. Start the Apache service using 'systemctl start apache2' (Debian/Ubuntu) or 'systemctl start httpd' (RHEL/CentOS)
  7. Verify the upgrade by running 'httpd -v' or 'apache2 -v' to confirm version 2.4.64
Caveat Minor version upgrade within 2.4.x series; minimal breaking change risk; review release notes for any module-specific changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in HTTP Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-42516 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data