dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2024-27316

HIGH · 7.5 CVSS v3.1 Published 2024-04-04
Fix available
A fix is available. Upgrade to 2.4.59 or later.
See remediation →
84/100
Remediation priority · High
High EPSS 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/2 incoming headers exceeding the limit are temporarily buffered in nghttp2 in order to generate an informative HTTP 413 response. If a client does not stop sending headers, this leads to memory exhaustion.

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

In nghttp2, when HTTP/2 incoming headers exceed the configured limit, they are temporarily buffered in memory to generate an informative HTTP 413 error response. If a malicious or misbehaving client continues sending headers without stopping, this causes unbounded memory allocation leading to memory exhaustion and denial of service.

MitigationImplement strict limits on header buffer allocation or switch to streaming rejection of oversized headers without full buffering; consider adding connection-level rate limiting or header count throttling at the application layer.

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:>= 2.4.17, < 2.4.59
FedoraOperating system
Affected:= 38= 39= 40
OntapApplication
Affected:= 9

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
None
Availability
High

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

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. Identify Apache HTTP Server installation
    Run 'httpd -v' or 'apache2 -v' to retrieve the installed version number
    Affected if The version is >= 2.4.17 and < 2.4.59
  2. Confirm HTTP/2 module is enabled
    Check if mod_http2 is loaded: 'httpd -M' or 'apache2ctl -M' lists http2_module, or check config files for 'LoadModule http2_module'
    Affected if HTTP/2 module (mod_http2) is loaded and active
  3. Verify HTTP/2 protocol is in use
    Review Apache config for 'Protocols h2 h2c' or 'Protocols h2' directive in the main config or virtual host
    Affected if The server accepts HTTP/2 connections (h2 or h2c)
  4. Check header limit configuration
    Search config for header-related directives like 'RequestHeaderSize', 'HeaderBufferSize', or custom LimitRequestFieldSize values - if not explicitly set, defaults apply
    Affected if Header limits exist but are not configured with strict bounds, or the defaults allow unbounded buffering behavior

You are affected if Apache HTTP Server version is between 2.4.17 and 2.4.58 inclusive, HTTP/2 is enabled, and the server handles HTTP/2 connections with default or permissive header buffering settings.

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 2.4.59 or later
Fixed in 2.4.59
Interim mitigation

Implement strict limits on header buffer allocation or switch to streaming rejection of oversized headers without full buffering; consider adding connection-level rate limiting or header count throttling at the application layer.

Recommended fix High confidence

Apache HTTP Server 2.4.59 or later

  1. 1. Identify the current Apache HTTP Server version using 'httpd -v' or 'apache2 -v'
  2. 2. Stop the Apache service using 'systemctl stop httpd' or 'systemctl stop apache2'
  3. 3. Update the package manager repository: 'dnf check-update' (Fedora) or 'apt-get update' (Debian)
  4. 4. Install the updated Apache package: 'dnf update httpd' (Fedora) or 'apt-get install apache2' (Debian)
  5. 5. Verify the new version is 2.4.59 or later using 'httpd -v'
  6. 6. Restart the Apache service using 'systemctl start httpd' or 'systemctl start apache2'
  7. 7. Test HTTP/2 functionality to ensure the service is working correctly
Caveat Minor - this is a security patch release; no breaking changes expected for typical configurations

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

Fix this in HTTP Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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-2024-27316 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