Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.31, 21.2.23, and 22.1.6, the @angular/platform-server DOM emulation parser can enter an infinite synchronous loop when Angular server-side rendering processes attacker-controlled HTML containing an incomplete DOCTYPE that ends with whitespace at end of input. In Domino lib/HTMLParser.js, after_doctype_name_state emits doctype and EOF tokens without advancing nextchar or leaving the fixed-lookahead state, so the scanner repeatedly handles the same EOF marker. A remote unauthenticated attacker can use this condition through server-side HTML parsing paths such as innerHTML binding to consume a Node.js SSR worker at full CPU, starve the event loop, and stop concurrent and subsequent requests. This issue is fixed in versions 20.3.31, 21.2.23, and 22.1.6.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Network (N)
|
Exploit possible à distance via réseau (HTTP, API, etc.) |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
None (N)
|
Aucune authentification requise |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
Angular SSR: Denial of Service (DoS) via Infinite Loop on Malformed DOCTYPE
Angular SSR: Denial of Service (DoS) via Infinite Loop on Malformed DOCTYPE