Thanks to visit codestin.com
Credit goes to github.com

Skip to content

Angular SSR: Global Platform Injector Race Condition Leads to Cross-Request Data Leakage

High
jkrems published GHSA-68x2-mx4q-78m7 Sep 10, 2025

Package

Codestin Search App @angular/platform-server (npm)

Affected versions

>= 16.0.0-next.0, < 18.2.14
>= 20.0.0-next.0, < 20.3.0
>= 19.0.0-next.0, < 19.2.15
>= 21.0.0-next.0, < 21.0.0-next.3

Patched versions

18.2.14
20.3.0
19.2.15
21.0.0-next.3
Codestin Search App @angular/ssr (npm)
>= 17.0.0-next.0, < 18.2.21
>= 19.0.0-next.0, < 19.2.16
>= 20.0.0-next.0, < 20.3.0
>= 21.0.0-next.0, < 21.0.0-next.3
18.2.21
19.2.16
20.3.0
21.0.0-next.3
Codestin Search App @nguniversal/common (npm)
>= 16.0.0-next.0, <= 16.2.0
None

Description

Impact

Angular uses a DI container (the "platform injector") to hold request-specific state during server-side rendering. For historical reasons, the container was stored as a JavaScript module-scoped global variable. When multiple requests are processed concurrently, they could inadvertently share or overwrite the global injector state.

In practical terms, this can lead to one request responding with data meant for a completely different request, leaking data or tokens included on the rendered page or in response headers. As long as an attacker had network access to send any traffic that received a rendered response, they may have been able to send a large number of requests and then inspect the responses for information leaks.

The following APIs were vulnerable and required SSR-only breaking changes:

  • bootstrapApplication: This function previously implicitly retrieved the last platform injector that was created. It now requires an explicit BootstrapContext in a server environment. This function is only used for standalone applications. NgModule-based applications are not affected.
  • getPlatform: This function previously returned the last platform instance that was created. It now always returns null in a server environment.
  • destroyPlatform: This function previously destroyed the last platform instance that was created. It's now a no-op when called in a server environment.

For bootstrapApplication, the framework now provides a new argument to the application's bootstrap function:

// Before:
const bootstrap = () => bootstrapApplication(AppComponent, config);

// After:
const bootstrap = (context: BootstrapContext) =>
  bootstrapApplication(AppComponent, config, context);

As is usually the case for changes to Angular, an automatic schematic will take care of these code changes as part of ng update:

# For apps on Angular v20:
ng update @angular/cli @angular/core

# For apps on Angular v19:
ng update @angular/cli@19 @angular/core@19

# For apps on Angular v18:
ng update @angular/cli@18 @angular/core@18

The schematic can also be invoked explicitly if the version bump was pulled in independently:

# For apps on Angular v20:
ng update @angular/core --name add-bootstrap-context-to-server-main

# For apps on Angular v19:
ng update @angular/core@19 --name add-bootstrap-context-to-server-main

# For apps on Angular v18:
ng update @angular/core@18 --name add-bootstrap-context-to-server-main

For applications that still use CommonEngine, the bootstrap property in CommonEngineOptions also gains the same context argument in the patched versions of Angular.

In local development (ng serve), Angular CLI triggered a codepath for Angular's "JIT" feature on the server even in applications that weren't using it in the browser. The codepath introduced async behavior between platform creation and application bootstrap, triggering the race condition even if an application didn't explicitly use getPlatform or custom async logic in bootstrap. Angular applications should never run in this mode outside of local development.

Patches

The issue has been patched in all active release lines as well as in the v21 prerelease:

  • @angular/platform-server: 21.0.0-next.3

  • @angular/platform-server: 20.3.0

  • @angular/platform-server: 19.2.15

  • @angular/platform-server: 18.2.14

  • @angular/ssr: 21.0.0-next.3

  • @angular/ssr: 20.3.0

  • @angular/ssr: 19.2.16

  • @angular/ssr: 18.2.21

Workarounds

  • Disable SSR via Server Routes (v19+) or builder options.
  • Remove any asynchronous behavior from custom bootstrap functions.
  • Remove uses of getPlatform() in application code.
  • Ensure that the server build defines ngJitMode as false.

References

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction Passive
Vulnerable System Impact Metrics
Confidentiality High
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVE ID

CVE-2025-59052

Weaknesses

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Learn more on MITRE.

Credits