CVE-2025-59052: Angular Information Disclosure Vulnerability

CVE-2025-59052 Overview

CVE-2025-59052 is a Race Condition vulnerability affecting Angular's Server-Side Rendering (SSR) functionality. Angular's dependency injection (DI) container, known as the "platform injector," stores request-specific state during SSR operations. Due to a historical implementation decision, this container was stored as a JavaScript module-scoped global variable, creating a shared state problem when multiple requests are processed concurrently.

When concurrent SSR requests occur, they can inadvertently share or overwrite the global injector state, leading to cross-request information leakage. This vulnerability can result in one request responding with data meant for a completely different request, potentially exposing sensitive tokens, user data, or other confidential information included on rendered pages or in response headers.

Critical Impact

Attackers with network access to Angular SSR applications can exploit concurrent request handling to intercept sensitive data, authentication tokens, and user information from other users' responses through timing-based race condition attacks.

Affected Products

• @angular/platform-server versions prior to 21.0.0-next.3, 20.3.0, 19.2.15, and 18.2.14
• @angular/ssr versions prior to 21.0.0-next.3, 20.3.0, 19.2.16, and 18.2.21
• Angular applications using Server-Side Rendering with the vulnerable bootstrapApplication, getPlatform, and destroyPlatform APIs

Discovery Timeline

• 2025-09-10 - CVE-2025-59052 published to NVD
• 2025-09-11 - Last updated in NVD database

Technical Details for CVE-2025-59052

Vulnerability Analysis

This vulnerability is classified as CWE-362 (Race Condition), specifically a Time-of-Check Time-of-Use (TOCTOU) variant affecting shared state management. The core issue stems from Angular's SSR architecture using a module-scoped global variable to store the platform injector, which should be request-isolated.

During server-side rendering, Angular bootstraps applications and maintains state through the platform injector. When multiple HTTP requests arrive concurrently, the single-threaded nature of JavaScript combined with asynchronous operations creates windows where one request's injector state can be accessed or modified by another request's processing context.

The vulnerable APIs include bootstrapApplication, getPlatform, and destroyPlatform. When these functions are called during concurrent request handling, the global injector state becomes a shared resource without proper synchronization, allowing cross-request data contamination.

Root Cause

The root cause is the use of a JavaScript module-scoped global variable to store the platform injector state during SSR operations. This architectural decision, made for historical reasons, creates a shared mutable state problem in concurrent execution environments. In Node.js SSR servers handling multiple simultaneous requests, this shared state lacks proper isolation mechanisms, allowing race conditions to occur during the injector lifecycle operations.

Attack Vector

An attacker can exploit this vulnerability by sending a high volume of requests to an Angular SSR application endpoint. The attack relies on timing manipulation to create race conditions during the application bootstrap and render phases.

The exploitation mechanism works as follows: when the server processes concurrent requests, there are critical windows during the platform creation, application bootstrap, and platform destruction phases where the global injector state can be accessed by competing requests. An attacker sending carefully timed requests can cause the server to return responses containing data, tokens, or rendered content intended for other users' sessions.

The attack requires only network access to the vulnerable SSR endpoint and does not require authentication or user interaction beyond passive victim requests to the same server. By analyzing responses from bulk requests, an attacker can identify information leaks and extract sensitive data from other users' server-rendered responses.

Detection Methods for CVE-2025-59052

Indicators of Compromise

• Unusual patterns in server response content showing data inconsistencies between user sessions
• Application logs indicating mismatched user context in rendered responses
• Reports from users receiving unexpected content or seeing other users' data
• Abnormally high concurrent request volumes to SSR endpoints from single sources

Detection Strategies

• Monitor application logs for signs of response data mismatches or user context inconsistencies
• Implement request correlation tracking to identify cross-request state pollution
• Analyze server metrics for concurrent request spikes that could indicate exploitation attempts
• Review HTTP response headers for leaked tokens or session data intended for other users

Monitoring Recommendations

• Enable detailed logging for SSR bootstrap and render operations to track injector lifecycle events
• Configure alerting for unusual concurrent request patterns targeting SSR endpoints
• Implement response content validation to detect cross-user data contamination
• Monitor for dependency version mismatches in deployment pipelines to ensure patched versions are deployed

How to Mitigate CVE-2025-59052

Immediate Actions Required

• Update @angular/platform-server to version 21.0.0-next.3, 20.3.0, 19.2.15, or 18.2.14 depending on your release line
• Update @angular/ssr to version 21.0.0-next.3, 20.3.0, 19.2.16, or 18.2.21 depending on your release line
• Audit application code for uses of getPlatform() and remove them if present
• Review custom bootstrap functions for asynchronous behavior that could extend race condition windows

Patch Information

Patches have been released across all active Angular release lines. The fixes address the underlying global state issue in the SSR platform injector through breaking changes to the vulnerable APIs. Detailed technical information about the patches can be found in Angular Pull Request #63562 and Angular CLI Pull Request #31108. The complete security advisory is available at GitHub Security Advisory GHSA-68x2-mx4q-78m7.

Workarounds

• Disable SSR entirely via Server Routes configuration or builder options if SSR is not critical to your application
• Remove any asynchronous behavior from custom bootstrap functions to minimize race condition windows
• Remove all uses of getPlatform() from application code
• Ensure the server build defines ngJitMode as false to reduce vulnerable code paths

# Update Angular packages to patched versions
npm update @angular/platform-server @angular/ssr

# Verify installed versions
npm list @angular/platform-server @angular/ssr

# For specific version installation
npm install @angular/platform-server@20.3.0 @angular/ssr@20.3.0