CVE intelligence and bounded remediation

CVE-2020-1673 — Juniper Junos security vulnerability

High CVSS 8.8

Insufficient Cross-Site Scripting (XSS) protection in Juniper Networks J-Web and web based (HTTP/HTTPS) services allows an unauthenticated attacker to hijack the target user's HTTP/HTTPS session and perform administrative actions on the Junos device as the targeted user. This issue only affects Juniper Networks Junos OS devices with HTTP/HTTPS services enabled such as J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP). Junos OS devices with HTTP/HTTPS services disabled are not affected. If HTTP/HTTPS services are enabled, the following command will show the httpd processes: user@device> show system processes | match http 5260 - S 0:00.13 /usr/sbin/httpd-gk -N 5797 - I 0:00.10 /usr/sbin/httpd --config /jail/var/etc/httpd.conf In order to successfully exploit this vulnerability, the attacker needs to convince the device administrator to take action such as clicking the crafted URL sent via phishing email or convince the administrator to input data in the browser console. This issue affects Juniper Networks Junos OS: 18.1 versions prior to 18.1R3-S1; 18.2 versions prior to 18.2R3-S5; 18.3 versions p…

Severity
High
CVSS
8.8 (3.1)
Published
2020-10-16
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-79

Affected products

  • juniper / junos / 18.1
  • juniper / junos / 18.2

Showing 2 representative product identities from 77 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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