XXE (XML External Entity) in libxml2 (CVE-2016-9318)
Summary
Vulnerability in libxml2 (CVE-2016-9318). Confidential information can be exposed externally.
Original description
The description as published by the source.
libxml2 2.9.4 and earlier, as used in XMLSec 1.2.23 and earlier and other products, does not offer a flag directly indicating that the current document may be read but other files may not be opened, which makes it easier for remote attackers to conduct XML External Entity (XXE) attacks via a crafted document.
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-2016-9318 has been found in libxml2.
Confidential information can be exposed externally. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "libxml2 CVE-2016-9318" on the vendor's site.
CVE-2016-9318 (libxml2) — CWE-611 / CVSS v3 5.5
Attack vector: local / unauthenticated
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.
A vulnerability (CWE-611) exists in libxml2.
Check the vendor advisory for the affected versions of libxml2.
Severity: Medium (CVSS 5.5/10). 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. Run grep -r 'libxml2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'libxml2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
libxml2を grep し、稼働しているサービス・バージョンを把握する。 -
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-2016-9318 libxml2 Fixed in: 2.9.4-r2
References
- advisory securityfocus.com
- advisory security.gentoo.org
- advisory usn.ubuntu.com
- advisory usn.ubuntu.com
- exploit github.com
- patch bugzilla.gnome.org
- web lists.debian.org
- web cert-portal.siemens.com