Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.32, 21.2.24, and 22.2.0, the @angular/router URL parser stores numeric matrix parameter names and numeric outlet names as properties on initially empty JavaScript objects during Node.js server-side rendering. V8 can interpret these URL-derived keys as array indices and allocate dense backing stores sized to high numeric values, so repeated small path segments cause disproportionate per-segment heap consumption. An unauthenticated attacker can send overlapping requests containing repeated numeric matrix parameters when SSR is enabled, the router directly parses the request URL, and upstream proxies allow semicolons and multiple path segments, eventually exhausting the Node.js old-space heap and terminating the SSR worker. Pure client-side Angular applications are not affected. This issue is fixed in versions 20.3.32, 21.2.24, and 22.2.0.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html
References
- https://github.com/angular/angular/commit/03872a80bcf1c89b2b04cdd3f444b2ee954da583
- https://github.com/angular/angular/commit/5af61216eab8bf4a6697a1d79bda3d857c06f89d
- https://github.com/angular/angular/commit/ddfe21072ba32ca4cd9d7d3c6b7df66af81d58c4
- https://github.com/angular/angular/issues/70716
- https://github.com/angular/angular/pull/70717
- https://github.com/angular/angular/releases/tag/v20.3.32
- https://github.com/angular/angular/releases/tag/v21.2.24
- https://github.com/angular/angular/releases/tag/v22.2.0
- https://github.com/angular/angular/security/advisories/GHSA-ff3f-86qr-9cv3