Use-After-Free in Apache Http Server (CVE-2017-9798)
Summary
Vulnerability in Apache Http Server (CVE-2017-9798). Confidential information can be exposed externally.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2017-9798 has been found in Apache Http Server.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Apache Http Server CVE-2017-9798" on the vendor's site.
CVE-2017-9798 (Apache Http Server) — CWE-416 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Use-after-free (CWE-416) exists in Apache Http Server.
Check the vendor advisory for the affected versions of Apache Http Server.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Apache Http Server を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2017-9798 apache2 Fixed in: 2.4.27-r1
References
- advisory openwall.com
- advisory debian.org
- advisory securityfocus.com
- advisory securityfocus.com
- advisory securitytracker.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory httpd.apache.org
- advisory security-tracker.debian.org
- advisory security.gentoo.org
- advisory security.netapp.com
- advisory support.apple.com
- advisory support.hpe.com
- advisory svn.apache.org
- advisory tenable.com
- patch oracle.com
- patch oracle.com
- patch oracle.com
- patch oracle.com
- patch blog.fuzzing-project.org
- patch blog.fuzzing-project.org
- patch github.com
- patch oracle.com
- patch oracle.com
- report github.com
- report exploit-db.com
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web lists.apache.org
- web seclists.org