Vulnerability · CVE-2017-9798
apache2 CVE-2017-9798
Published Feb 22, 2022 · catalog updated Feb 22, 2022 · Apache HTTP Server
Patch now
CVE-2017-9798 is in the CISA known-exploited catalog. Confirm Apache HTTP Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.
- Severity
- Unknown—
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 95.00%
- Remediation
- Remediation guidance
- Affected products
- alpine apache2 · vendor Apache HTTP Server
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 Initial-access exploit intelligence.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- alpine apache22.4.27-r1
- vendor Apache HTTP Serverversion unspecified
How to fix CVE-2017-9798
Recommended remediation
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2017-9798 is in the CISA known-exploited catalog. Confirm Apache HTTP Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with 2.4.27-r1. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
What should an analyst verify?
No weakness class is stored. EPSS 95.00%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Feb 22, 2022 · CISA KEV
Known exploited
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Oct 17, 2026 · Alpine Linux Security
Detected
CVE-2017-9798 is fixed in Alpine edge package apache2 2.4.27-r1 (main).
Sources
- Alpine Linux SecurityPackage advisoryCVE-2017-9798
CVE-2017-9798 is fixed in Alpine edge package apache2 2.4.27-r1 (main).
security.alpinelinux.org - CVE.orgVulnerability recordCVE-2017-9798
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2017-9798
30-day exploitation probability 95.0%
first.org - VulnCheck KEVConfirmed exploitationCVE-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, 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
vulncheck.com
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.