CVE-2018-8011
HighExploitedBy specially crafting HTTP requests, the mod_md challenge handler would dereference a NULL pointer and cause the child process to segfault.
Published Jul 18, 2018 · Updated Sep 23, 2026 · Also known as ALPINE-CVE-2018-8011, DEBIAN-CVE-2018-8011, UBUNTU-CVE-2018-8011
Key Facts
Patch immediately- CVE-2018-8011 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting HTTP Server (Apache), Cloud Backup (Netapp), apache (arch) 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 56% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.34-1, apache2 2.4.33-3.3.1, apache2 2.4.33-lp150.2.3.1.
- 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)
56%
Higher than 99.0% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
None known
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Description
By specially crafting HTTP requests, the mod_md challenge handler would dereference a NULL pointer and cause the child process to segfault. This could be used to DoS the server. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.33).
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
73 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | 2.4.33, >= Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.33) | n/a |
| Cloud BackupNetapp | See advisory | n/a |
| apachearch | See advisory | 2.4.34-1 |
| apache2alpine | See advisory | 2.4.34-r0 |
| rootio-apache2rootio | See advisory | 2.4.34-1 |
Patched Releases
apache
2.4.34-1
apache2
2.4.33-3.3.1, 2.4.33-lp150.2.3.1, 2.4.34-1, 2.4.34-r0
apache2-devel
2.4.33-3.3.1, 2.4.33-lp150.2.3.1
apache2-doc
2.4.33-3.3.1, 2.4.33-lp150.2.3.1
apache2-event
2.4.33-lp150.2.3.1
apache2-example-pages
2.4.33-lp150.2.3.1
apache2-prefork
2.4.33-3.3.1, 2.4.33-lp150.2.3.1
apache2-utils
2.4.33-3.3.1, 2.4.33-lp150.2.3.1
apache2-worker
2.4.33-3.3.1, 2.4.33-lp150.2.3.1
httpd
2.4.34-1.amzn2.1.0
httpd-devel
2.4.34-1.amzn2.1.0
httpd-filesystem
2.4.34-1.amzn2.1.0
httpd-manual
2.4.34-1.amzn2.1.0
httpd-tools
2.4.34-1.amzn2.1.0
httpd24
2.4.34-1.82.amzn1
httpd24-devel
2.4.34-1.82.amzn1
httpd24-manual
2.4.34-1.82.amzn1
httpd24-tools
2.4.34-1.82.amzn1
mod_ldap
2.4.34-1.amzn2.1.0
mod_md
2.4.34-1.amzn2.1.0
mod_proxy_html
1:2.4.34-1.amzn2.1.0
mod_session
2.4.34-1.amzn2.1.0
mod_ssl
1:2.4.34-1.amzn2.1.0
mod24_ldap
2.4.34-1.82.amzn1
mod24_md
2.4.34-1.82.amzn1
Timeline
Publicly disclosed
Jul 18, 2018
Added to Industry KEV feed
Feb 22, 2022
Last updated
Sep 23, 2026
Weakness Type
- CWE-476 NULL Pointer Dereference
References
- advisoryhttps://bugzilla.suse.com/1101688
- advisoryhttps://bugzilla.suse.com/1101689
- advisoryhttps://httpd.apache.org/security/vulnerabilities_24.html#CVE-2018-8011
- advisoryhttps://security.alpinelinux.org/vuln/CVE-2018-8011
- advisoryhttps://security.netapp.com/advisory/ntap-20180926-0007/
FAQ
Common Questions.
By specially crafting HTTP requests, the mod_md challenge handler would dereference a NULL pointer and cause the child process to segfault.
Affected: HTTP Server (Apache) versions 2.4.33, >= Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.33); Cloud Backup (Netapp); apache (arch), 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 2.4.34-1, apache2 2.4.33-3.3.1, apache2 2.4.33-lp150.2.3.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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