CVE-2018-1303
HighExploitedA 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.
Published Mar 26, 2018 · Updated Aug 4, 2026 · Also known as ALPINE-CVE-2018-1303, DEBIAN-CVE-2018-1303, UBUNTU-CVE-2018-1303
Key Facts
Patch immediately- CVE-2018-1303 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting HTTP Server (Apache), Santricity Cloud Connector (Netapp), Storage Automation Store (Netapp) and 22 more products.
- It is exploited in the wild, listed in Industry KEV feed since Feb 22, 2022. No public exploit code is known.
- EPSS estimates a 70% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.33-1, HTTP Server <=2.4.29, apache2 2.4.10-10+deb8u12.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
70%
Higher than 99.3% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
None known
Get the full CVE-2018-1303 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Feb 22, 2022 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
177 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | >= 2.4.5 to 2.4.29 | 2.4.29 |
| Santricity Cloud ConnectorNetapp | See advisory | n/a |
| Storage Automation StoreNetapp | See advisory | n/a |
| StoragegridNetapp | See advisory | n/a |
| Ubuntu LinuxCanonical | 14.04, 16.04, 17.10, 18.04 | n/a |
Patched Releases
apache
2.4.33-1
HTTP Server
<=2.4.29
apache2
2.4.10-10+deb8u12, 2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.18-2ubuntu3.8, 2.4.23-22.1, 2.4.23-29.18.2, 2.4.25-3+deb9u4, 2.4.29-1ubuntu4.1, 2.4.33-1, 2.4.33-r0, 2.4.7-1ubuntu4.20
apache2-devel
2.4.23-22.1, 2.4.23-29.18.2
apache2-doc
2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.23-22.1, 2.4.23-29.18.2
apache2-event
2.4.23-22.1
apache2-example-pages
2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.23-22.1, 2.4.23-29.18.2
apache2-prefork
2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.23-22.1, 2.4.23-29.18.2
apache2-utils
2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.23-22.1, 2.4.23-29.18.2
apache2-worker
2.4.10-14.31.1, 2.4.16-20.16.1, 2.4.23-22.1, 2.4.23-29.18.2
httpd
0:2.4.6-95.el7, 2.4.33-1.ph1, 2.4.33-1.ph2, 2.4.6-95.0.1.el7
httpd-devel
2.4.6-95.0.1.el7
httpd-manual
2.4.6-95.0.1.el7
httpd-tools
2.4.6-95.0.1.el7
httpd24
2.4.33-2.78.amzn1
httpd24-curl
0:7.61.1-1.el6, 0:7.61.1-1.el7
httpd24-devel
2.4.33-2.78.amzn1
httpd24-httpd
0:2.4.34-7.el6, 0:2.4.34-7.el7
httpd24-manual
2.4.33-2.78.amzn1
httpd24-nghttp2
0:1.7.1-7.el6, 0:1.7.1-7.el7
httpd24-tools
2.4.33-2.78.amzn1
jbcs-httpd24
0:1-6.jbcs.el6, 0:1-6.jbcs.el7
jbcs-httpd24-apache-commons-daemon-jsvc
1:1.1.0-3.redhat_2.jbcs.el6, 1:1.1.0-3.redhat_2.jbcs.el7
jbcs-httpd24-apr
0:1.6.3-31.jbcs.el6, 0:1.6.3-31.jbcs.el7
jbcs-httpd24-apr-util
0:1.6.1-24.jbcs.el6, 0:1.6.1-24.jbcs.el7
Timeline
Publicly disclosed
Mar 26, 2018
Added to Industry KEV feed
Feb 22, 2022
Last updated
Aug 4, 2026
Weakness Type
- CWE-125 Out-of-bounds Read
References
- advisoryRHSA-2018:3558
- advisoryRHSA-2019:0366
- advisoryRHSA-2019:0367
- advisoryRHSA-2020:3958
- advisoryhttps://bugzilla.suse.com/1057406
FAQ
Common Questions.
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.
Affected: HTTP Server (Apache) versions >= 2.4.5 to 2.4.29; Santricity Cloud Connector (Netapp); Storage Automation Store (Netapp), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Feb 22, 2022.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including apache 2.4.33-1, HTTP Server <=2.4.29, apache2 2.4.10-10+deb8u12.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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