NVD / CVE Program· CNA apache

CVE-2017-9798: 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…

HighCVSS 7.5 · v3.1—Weaponized Fix available

Noroxi assessment

Priority: This week (action score 60/100)

A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
A ready-made attack tool exists and the flaw can be exploited over the network without an account, so priority is at least “This week”.
Probability of exploitation in the next 30 days: 94.6% (FIRST EPSS); higher than 99.8% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: apache2 (Alpine:v3.10) 2.4.27-r1; apache2 (Debian:12) 2.4.27-6; apache2 (Debian:7) 2.2.22-13+deb7u12.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Don’t wait for the next maintenance window. Upgrade to apache2 (Alpine:v3.10) 2.4.27-r1; apache2 (Debian:12) 2.4.27-6; apache2 (Debian:7) 2.2.22-13+deb7u12 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published: Sep 18, 2017
Updated: Jun 16, 2026
EPSS: 94.6% · 99th percentile
CWE: CWE-416

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Action score

This week

Don’t wait for the next maintenance window.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 28 / 30 · 94.6%
Ready-made attack tool: 2 / 60 · floor: at least 60

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Weaponized exploit exists
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
apache	http server	cpe:2.3:a:apache:http_server
debian	debian linux	cpe:2.3:o:debian:debian_linux

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

Apache Software Foundation Apache HTTP Server
- Apache HTTP Server through 2.2.34 and 2.4.x through 2.4.27affected

Affected versions · NVD (19)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apache http serverup to 2.2.34 inclusive
apache http server2.4.0
apache http server2.4.1
apache http server2.4.10
apache http server2.4.12
apache http server2.4.16
apache http server2.4.17
apache http server2.4.18
apache http server2.4.2
apache http server2.4.20
apache http server2.4.23
apache http server2.4.25
apache http server2.4.26
apache http server2.4.27
apache http server2.4.3
apache http server2.4.4
apache http server2.4.6
apache http server2.4.7
apache http server2.4.9

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Alpine:v3.10	apache2	before 2.4.27-r1	2.4.27-r1
Debian:12	apache2	before 2.4.27-6	2.4.27-6
Debian:7	apache2	before 2.2.22-13+deb7u12	2.2.22-13+deb7u12
Debian:8	apache2	before 2.4.10-10+deb8u11	2.4.10-10+deb8u11
Debian:9	apache2	before 2.4.25-3+deb9u3	2.4.25-3+deb9u3
Red Hat:enterprise_linux:6::client	httpd	before 0:2.2.15-60.el6_9.6	0:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:6::client	httpd-debuginfo	before 0:2.2.15-60.el6_9.6	0:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:6::client	httpd-devel	before 0:2.2.15-60.el6_9.6	0:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:6::client	httpd-manual	before 0:2.2.15-60.el6_9.6	0:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:6::client	httpd-tools	before 0:2.2.15-60.el6_9.6	0:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:6::client	mod_ssl	before 1:2.2.15-60.el6_9.6	1:2.2.15-60.el6_9.6
Red Hat:enterprise_linux:7::client	httpd	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	httpd-debuginfo	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	httpd-devel	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	httpd-manual	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	httpd-tools	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	mod_ldap	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	mod_proxy_html	before 1:2.4.6-67.el7_4.5	1:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	mod_session	before 0:2.4.6-67.el7_4.5	0:2.4.6-67.el7_4.5
Red Hat:enterprise_linux:7::client	mod_ssl	before 1:2.4.6-67.el7_4.5	1:2.4.6-67.el7_4.5
Red Hat:jboss_core_services:1::el6	jbcs-httpd24-httpd	before 0:2.4.23-125.jbcs.el6	0:2.4.23-125.jbcs.el6
Red Hat:jboss_core_services:1::el6	jbcs-httpd24-httpd-debuginfo	before 0:2.4.23-125.jbcs.el6	0:2.4.23-125.jbcs.el6
Red Hat:jboss_core_services:1::el6	jbcs-httpd24-httpd-devel	before 0:2.4.23-125.jbcs.el6	0:2.4.23-125.jbcs.el6
Red Hat:jboss_core_services:1::el6	jbcs-httpd24-httpd-libs	before 0:2.4.23-125.jbcs.el6	0:2.4.23-125.jbcs.el6

+96

Same product

apache: all records

Other highest-scoring records for the same primary product.

CVE-2021-42013Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)KEV
99Now
CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV
99Now
CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV
96Now

Published before and after this one in the same product

← EarlierCVE-2016-2161Jul 27, 2017 · In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance…
36Monitor
← EarlierCVE-2016-8743Jul 27, 2017 · Apache HTTP Server, in all releases prior to 2.2.32 and 2.4.25, was liberal in the whitespace accepted from requests and sent in response…
34Monitor
Later →CVE-2016-8612Mar 9, 2018 · Apache HTTP Server mod_cluster before version httpd 2.4.23 is vulnerable to an Improper Input Validation in the protocol parsing logic in…
18Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
alpine:apache2	2.4.27-r1 · Alpine:v3.10	Package registry (OSV)
debian:apache2	2.4.27-6 · Debian:12	Package registry (OSV)
red hat:httpd	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:httpd-debuginfo	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:httpd-devel	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:httpd-manual	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:httpd-tools	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:httpd24	0:1.1-18.el6 · Red Hat:rhel_software_collections:3::el6	Package registry (OSV)
red hat:httpd24-httpd	0:2.4.27-8.el6 · Red Hat:rhel_software_collections:3::el6	Package registry (OSV)
red hat:httpd24-httpd-debuginfo	0:2.4.27-8.el6 · Red Hat:rhel_software_collections:3::el6	Package registry (OSV)
red hat:mod_ldap	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:mod_proxy_html	1:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:mod_session	0:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
red hat:mod_ssl	1:2.4.6-67.el7_4.5 · Red Hat:enterprise_linux:7::client	Package registry (OSV)
suse:apache2	2.4.23-29.6.1 · SUSE:Linux Enterprise Server for Raspberry Pi 12 SP2	Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

Metasploit module ×1
Exploit-DB entry ×1
Proof-of-concept repository on GitHub ×4

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	4 repositories	2017-09-18 → 2017-09-27
Exploit-DB entry	webapps	2017-09-18
Metasploit module	auxiliary/scanner/http/apache_optionsbleedApache Optionsbleed Scannerauxiliary	2017-09-18

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

First PoCSep 18, 2017same day
MetasploitSep 18, 2017same day
PublishedSep 18, 2017
TodayNov 15, 2026+3345 d

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

apache/httpdcommit 4cc2782

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-17-122 · Sep 21, 2017(Kritik Apache Optionsbleed Zafiyeti)

All national notices →

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:47 PM UTC

For records you follow, these changes also arrive as notifications. →

References

openwall.com/lists/oss-security/2017/09/18/2

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Noroxi analysis

What does it mean in your environment?

We use this product, ask for help

Data sources and verification

CNA: apache

CVE.org (CNA)Nov 4, 2025, 4:09 PM UTC
NVDJun 16, 2026, 9:28 PM UTC
FIRST EPSSNov 12, 2026, 12:00 AM UTC
OSV / GHSANov 15, 2026, 3:15 AM UTC
Exploit-DBNov 15, 2026, 3:15 AM UTC
MetasploitNov 15, 2026, 3:15 AM UTC
PoC-in-GitHubNov 15, 2026, 3:15 AM UTC

Each line is when that source was last processed for this record.

CVE-2017-9798: 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…

Noroxi assessment

Get told when this record changes

Follow CVE-2017-9798

What does it mean in your environment?

Affected systems

Is your version affected?

Watch new CVEs for http server

Versions reported by the vendor

Package-level exposure

Same product

Remediation

Which version to upgrade to

Exploit status

Research context

Timeline

Patch and commit links

National notice (Türkiye Cybersecurity Directorate / USOM)

Technical details

Attack conditions

If successful

Root cause

The bug in code

Attack context

References