dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2018-1303

HIGH · 7.5 CVSS v3.0 Published 2018-03-26
Fix available
A fix is available. Upgrade to after 2.4.29 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
A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of mod_cache_socache. The vulnerability is considered as low risk since mod_cache_socache is not widely used, mod_cache_disk is not concerned by this vulnerability.

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

Apache HTTP Server versions prior to 2.4.30 contain an out-of-bounds read vulnerability in mod_cache_socache. When preparing HTTP request header data for caching in shared memory, a specially crafted request header triggers the out-of-bounds read, causing a crash and enabling denial of service attacks against affected deployments.

MitigationUpgrade Apache HTTP Server to version 2.4.30 or later. Alternatively, disable mod_cache_socache if not required, as mod_cache_disk is not affected.

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:<= 2.4.29
Debian LinuxOperating system
Affected:= 8.0= 9.0
Ubuntu LinuxOperating system
Affected:= 14.04= 16.04= 17.10= 18.04
Santricity Cloud ConnectorApplication
Affected:all versions
Storage Automation StoreApplication
Affected:all versions
StoragegridApplication
Affected:all versions
Clustered Data OntapOperating system
Affected:all versions

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:3.0/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 installed Apache HTTP Server version
    Run 'apache2 -v' or 'httpd -v' to display the server version. On Debian/Ubuntu, also check '/usr/sbin/apache2 -v'
    Affected if Version is 2.4.29 or lower
  2. Verify mod_cache_socache module is loaded
    Run 'apache2ctl -M' or 'httpd -M' to list loaded modules. Look for 'mod_cache_socache' or 'cache_socache_module' in the output
    Affected if mod_cache_socache appears in the loaded modules list
  3. Check Apache configuration for cache configuration
    Examine Apache config files (commonly in /etc/apache2, /etc/httpd/conf, or /etc/apache2/mods-enabled/) for any 'CacheSocache' directives or includes of mod_cache_socache configuration
    Affected if Configuration contains directives loading or enabling mod_cache_socache (e.g., 'LoadModule cache_socache_module' or 'CacheSocache' settings)
  4. Confirm cache module type in use
    Review configuration files for any 'CacheSocache' directives. If present alongside 'mod_cache_socache' being loaded, the vulnerability is applicable
    Affected if Configuration explicitly uses socache-based caching (CacheSocache directive) rather than only disk-based caching
  5. Verify NetApp product installations if applicable
    For NetApp products listed (Santricity Cloud Connector, Storage Automation Store, StorageGRID, Clustered Data ONTAP), consult vendor documentation or check installed package versions as these products bundle Apache
    Affected if Any of these NetApp products are running and bundle the affected Apache version

You are affected if Apache HTTP Server version is 2.4.29 or lower AND mod_cache_socache is both loaded and actively configured for use in your deployment.

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.

From vendor data
Upgrade available Upgrade to a release after 2.4.29
Interim mitigation

Upgrade Apache HTTP Server to version 2.4.30 or later. Alternatively, disable mod_cache_socache if not required, as mod_cache_disk is not affected.

Fix this in HTTP Server Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

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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-2018-1303 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