CVE-2017-9798
HighExploitedPublic exploitApache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file, or if httpd.conf has certain misconfigurations, aka Optionsbleed.
Published Sep 18, 2017 · Updated Aug 4, 2026 · Also known as ALPINE-CVE-2017-9798, DEBIAN-CVE-2017-9798, DLA-1102-1, DSA-3980-1, SUSE-SU-2017:2542-1, SUSE-SU-2017:2718-1, UBUNTU-CVE-2017-9798, USN-3425-1
Key Facts
Patch immediately- CVE-2017-9798 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting HTTP Server (Apache), Debian Linux, apache (arch) and 22 more products.
- It is exploited in the wild, listed in Industry KEV feed since Feb 22, 2022 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 95% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.27-2, HTTP Server 2.2.34, apache2 2.2.22-13+deb7u12.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
95%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2017-9798 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Apache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file, or if httpd.conf has certain misconfigurations, aka Optionsbleed. This affects the Apache HTTP Server through 2.2.34 and 2.4.x through 2.4.27. The attacker sends an unauthenticated OPTIONS HTTP request when attempting to read secret data. This is a use-after-free issue and thus secret data is not always sent, and the specific data depends on many factors including configuration. Exploitation with .htaccess can be blocked with a patch to the ap_limit_section function in server/core.c.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Feb 22, 2022 | n/a | Known |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
261 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | 2.4.0, 2.4.1, 2.4.10, 2.4.12, 2.4.16, 2.4.17, 2.4.18, 2.4.2 | 2.2.34 |
| Debian LinuxDebian | 7.0, 8.0, 9.0 | n/a |
| apachearch | See advisory | 2.4.27-2 |
| apache2alpine | See advisory | 2.4.27-r1 |
| rootio-apache2rootio | See advisory | 2.4.27-6 |
Patched Releases
apache
2.4.27-2
HTTP Server
2.2.34
apache2
2.2.22-13+deb7u12, 2.2.34-70.12.1, 2.4.10-10+deb8u11, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.18-2ubuntu3.5, 2.4.23-16.1, 2.4.23-29.6.1, 2.4.25-3+deb9u3, 2.4.27-6, 2.4.27-r1, 2.4.49-1.1, 2.4.7-1ubuntu4.18
apache2-devel
2.2.34-70.12.1, 2.4.23-16.1, 2.4.23-29.6.1
apache2-doc
2.2.34-70.12.1, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.23-16.1, 2.4.23-29.6.1
apache2-event
2.4.23-16.1
apache2-example-pages
2.2.34-70.12.1, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.23-16.1, 2.4.23-29.6.1
apache2-prefork
2.2.34-70.12.1, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.23-16.1, 2.4.23-29.6.1
apache2-utils
2.2.34-70.12.1, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.23-16.1, 2.4.23-29.6.1
apache2-worker
2.2.34-70.12.1, 2.4.10-14.28.1, 2.4.16-20.13.1, 2.4.23-16.1, 2.4.23-29.6.1
httpd
0:2.2.15-47.el6_7.5, 0:2.4.6-40.el7_2.6, 2.2.15-60.0.1.el6_9.6, 2.2.34-1.15.amzn1, 2.4.28-1.ph1, 2.4.28-1.ph2, 2.4.6-67.0.1.el7_4.5
httpd-devel
2.2.15-60.0.1.el6_9.6, 2.2.34-1.15.amzn1, 2.4.6-67.0.1.el7_4.5
httpd-manual
2.2.15-60.0.1.el6_9.6, 2.2.34-1.15.amzn1, 2.4.6-67.0.1.el7_4.5
httpd-tools
2.2.15-60.0.1.el6_9.6, 2.2.34-1.15.amzn1, 2.4.6-67.0.1.el7_4.5
httpd22
0:2.2.26-58.ep6.el7
httpd24
0:1.1-18.el6, 0:1.1-18.el7, 2.4.27-3.73.amzn1
httpd24-curl
0:7.47.1-4.el7
httpd24-devel
2.4.27-3.73.amzn1
httpd24-httpd
0:2.4.27-8.el6, 0:2.4.27-8.el7
httpd24-manual
2.4.27-3.73.amzn1
httpd24-mod_auth_kerb
0:5.4-33.el7
httpd24-nghttp2
0:1.7.1-6.el7
httpd24-tools
2.4.27-3.73.amzn1
jbcs-httpd24-httpd
0:2.4.23-125.jbcs.el6, 0:2.4.23-125.jbcs.el7
jbcs-httpd24-mod_bmx
0:0.9.6-15.GA.jbcs.el6, 0:0.9.6-15.GA.jbcs.el7
Timeline
Publicly disclosed
Sep 18, 2017
Added to Industry KEV feed
Feb 22, 2022
Last updated
Aug 4, 2026
Weakness Type
- CWE-416 Use After Free
References
- advisoryRHSA-2017:2882
- advisoryRHSA-2017:2972
- advisoryRHSA-2017:3018
- advisoryRHSA-2017:3113
- advisoryRHSA-2017:3114
FAQ
Common Questions.
Apache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file, or if httpd.conf has certain misconfigurations, aka Optionsbleed.
Affected: HTTP Server (Apache) versions 2.4.0, 2.4.1, 2.4.10, 2.4.12, 2.4.16, 2.4.17, 2.4.18, 2.4.2; Debian Linux versions 7.0, 8.0, 9.0; 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 and is known to be used in ransomware campaigns.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including apache 2.4.27-2, HTTP Server 2.2.34, apache2 2.2.22-13+deb7u12.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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