CVE-2025-59983 Overview
CVE-2025-59983 is a stored Cross-Site Scripting (XSS) vulnerability [CWE-79] in Juniper Networks Junos Space. Attackers can inject script tags in the Template Definition page. When another user, including an administrator, views the affected page, the injected script executes with that user's permissions. The flaw affects all versions of Junos Space before 24.1R4. Juniper published advisory JSA103140 addressing the issue.
Critical Impact
Successful exploitation allows an attacker to execute arbitrary commands in the browser context of any user who views the malicious Template Definition page, including administrators managing the network device orchestration platform.
Affected Products
- Juniper Junos Space, all versions before 24.1R4
- Juniper Junos Space 24.1R1
- Juniper Junos Space 24.1R2 and 24.1R3
Discovery Timeline
- 2025-10-09 - CVE-2025-59983 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-59983
Vulnerability Analysis
The vulnerability resides in the Template Definition page of the Junos Space web management interface. Junos Space fails to properly neutralize user-supplied input during web page generation. An authenticated attacker can submit script content that Junos Space stores and later renders inside another user's browser session.
When a victim, such as an administrator, loads the affected page, the browser parses and executes the injected script within the trusted origin of the Junos Space console. The script inherits the victim's session and can invoke administrative functions available to that user.
Junos Space centralizes management for Juniper network devices, so an administrator session carries substantial authority. Compromising it may lead to configuration changes, credential theft, or pivot into managed devices.
Root Cause
The root cause is missing or insufficient output encoding on values rendered in the Template Definition page. The application accepts input containing HTML or JavaScript control characters and writes them to the response without contextual escaping, allowing script tags to be interpreted as executable code by the browser.
Attack Vector
The attack vector is network-based and requires user interaction. An attacker with the ability to create or modify template definitions injects a malicious payload into a stored field. The payload triggers when a second user opens the Template Definition page. Because the payload runs in the victim's browser, actions occur under the victim's identity and privilege level.
No verified exploit code is publicly available. The vulnerability has an EPSS score of 0.256%.
See the Juniper Security Advisory JSA103140 for vendor-provided technical details.
Detection Methods for CVE-2025-59983
Indicators of Compromise
- Template Definition records containing <script>, onerror=, onload=, javascript:, or encoded variants of these tokens.
- Unexpected administrative actions in Junos Space audit logs originating from browser sessions shortly after a user viewed a Template Definition page.
- HTTP responses from the Junos Space UI that echo user-controlled template fields without HTML entity encoding.
Detection Strategies
- Review Junos Space database entries and template exports for HTML or JavaScript content in fields intended for plain text.
- Deploy Content Security Policy (CSP) reporting on the Junos Space origin, if supported, to capture inline script execution attempts.
- Correlate template creation or modification events with subsequent administrative API calls from the same session.
Monitoring Recommendations
- Enable and forward Junos Space audit logs and web access logs to a centralized SIEM for retention and correlation.
- Alert on template creation or edit events performed by low-privilege users followed by administrator sessions opening the same records.
- Monitor outbound connections from administrator browsers to unfamiliar domains, which may indicate script beaconing.
How to Mitigate CVE-2025-59983
Immediate Actions Required
- Upgrade Junos Space to version 24.1R4 or later, per Juniper advisory JSA103140.
- Restrict access to the Junos Space management interface to trusted administrative networks only.
- Audit existing Template Definitions for embedded HTML or script content and remove suspicious entries before administrators access them.
- Rotate credentials and session tokens for administrator accounts that may have viewed tampered template pages.
Patch Information
Juniper Networks addressed CVE-2025-59983 in Junos Space 24.1R4. Refer to the Juniper Security Advisory JSA103140 for the full list of fixed releases and upgrade guidance.
Workarounds
- Limit template creation and edit permissions to a minimal set of trusted users until the patch is applied.
- Require administrators to use a dedicated management browser profile with no saved credentials for other services.
- Place the Junos Space UI behind a reverse proxy that enforces a strict Content Security Policy blocking inline scripts.
# Verify Junos Space version after upgrade
ssh admin@<junos-space-host> "rpm -qa | grep -i jmp-platform"
# Expected output should reflect release 24.1R4 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
