CVE-2018-1303: Apache Software Foundation Apache HTTP Server…

CVE-2018-1303: A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 d...

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.

UnknownCVSS not scoredNot KEV-listedUpdatedSep 17, 2024, 02:10 UTC (UTC+00:00)

Security readout for executives and security teams

Plain-English summary

CVE-2018-1303 is a denial-of-service issue in Apache HTTP Server before 2.4.30. A specially crafted HTTP request header could crash servers using mod_cache_socache. The source states this is low risk because that module is not widely used, and mod_cache_disk is not affected.

Executive priority

Treat this as a targeted availability risk, not a broad emergency. Remediate during normal patch cycles unless exposed systems actively use mod_cache_socache or have business-critical uptime requirements.

Technical view

Apache httpd 2.4.5 through 2.4.29 can perform an out-of-bounds read while preparing data for shared-memory caching in mod_cache_socache. The documented impact is process crash and denial of service. The affected condition depends on mod_cache_socache use, not general Apache caching.

Likely exposure

Exposure is most likely on Apache HTTP Server 2.4.5-2.4.29 deployments with mod_cache_socache enabled. Systems using mod_cache_disk alone are not identified as affected in the source bundle.

Exploitation context

The sources describe a crafted HTTP request header causing denial of service. The bundle does not show CISA KEV listing or cited evidence of active exploitation, so active exploitation should not be claimed.

Researcher notes

Key uncertainty is environmental: the vulnerable path depends on mod_cache_socache. CVSS data is absent in the bundle, but Apache’s description calls the issue low risk. Validate module usage before estimating fleet impact.

Mitigation direction

Upgrade Apache HTTP Server to 2.4.30 or a vendor-fixed backport.
Disable mod_cache_socache where it is not required.
Review Debian, Ubuntu, Red Hat, NetApp, or HPE advisories for packaged fixes.
Prioritize internet-facing servers that use shared-memory caching.

Validation and detection

Inventory Apache HTTP Server versions across public and internal hosts.
Check whether mod_cache_socache is enabled in Apache configuration.
Confirm installed packages include the vendor fix for CVE-2018-1303.
Verify mod_cache_disk-only deployments are not treated as vulnerable.
Review service crash history for unexplained Apache worker failures.

Prepared: Jun 7, 2026, 14:22 UTC (UTC+00:00)
Confidence: high
Sources: 8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2018-1303 mapping review

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Mar 26, 2018, 15:00 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

23Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
USN-3627-1CVE reference · vendor-advisory, x_refsource_UBUNTU
DSA-4164CVE reference · vendor-advisory, x_refsource_DEBIAN
https://security.netapp.com/advisory/ntap-20180601-0004/CVE reference · x_refsource_CONFIRM
RHSA-2018:3558CVE reference · vendor-advisory, x_refsource_REDHAT
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03909en_usCVE reference · x_refsource_CONFIRM
RHSA-2019:0367CVE reference · vendor-advisory, x_refsource_REDHAT
USN-3627-2CVE reference · vendor-advisory, x_refsource_UBUNTU
https://httpd.apache.org/security/vulnerabilities_24.htmlCVE reference · x_refsource_CONFIRM
RHSA-2019:0366CVE reference · vendor-advisory, x_refsource_REDHAT
[httpd-cvs] 20190815 svn commit: r1048743 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20190815 svn commit: r1048742 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST
https://www.tenable.com/security/tns-2019-09CVE reference · x_refsource_CONFIRM
[httpd-cvs] 20200401 svn commit: r1058586 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20200401 svn commit: r1058587 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073143 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073140 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073139 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1888194 [11/13] - /httpd/site/trunk/content/security/json/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210330 svn commit: r1073149 [12/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/CVE reference · mailing-list, x_refsource_MLIST
[httpd-cvs] 20210606 svn commit: r1075470 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.htmlCVE reference · mailing-list, x_refsource_MLIST

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

Apache Software FoundationApache HTTP Server2.4.5 to 2.4.29Listed

Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.