Cross-Site Scripting (XSS) in Juniper Junos (CVE-2016-4923)
Summary
Cross-site scripting in Juniper Junos (CVE-2016-4923). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
Insufficient cross site scripting protection in J-Web component in Juniper Networks Junos OS may potentially allow a remote unauthenticated user to inject web script or HTML and steal sensitive data and credentials from a J-Web session and to perform administrative actions on the Junos device. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.1X44 prior to 12.1X44-D60; 12.1X46 prior to 12.1X46-D40; 12.1X47 prior to 12.1X47-D30; 12.3 prior to 12.3R11; 12.3X48 prior to 12.3X48-D20; 13.2X51 prior to 13.2X51-D39, 13.2X51-D40; 13.3 prior to 13.3R9; 14.1 prior to 14.1R6; 14.2 prior to 14.2R6; 15.1 prior to 15.1R3; 15.1X49 prior to 15.1X49-D20; 15.1X53 prior to 15.1X53-D57.
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-2016-4923 has been found in Juniper Junos.
Successful exploitation can lead to full system takeover. CVSS score: 8.0/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Juniper Junos CVE-2016-4923" on the vendor's site.
CVE-2016-4923 (Juniper Junos) — CWE-79 / CVSS v3 8.0
Attack vector: remote (network-reachable)
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.
Cross-site scripting (XSS) (CWE-79) exists in Juniper Junos.
Check the vendor advisory for the affected versions of Juniper Junos.
Severity: High (CVSS 8.0/10). Successful exploitation can lead to full system takeover.
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 'Junos' . 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 'Junos' . | 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
Junos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。
References
- advisory securityfocus.com
- patch kb.juniper.net