ewe is a Gleam web server. Versions 0.8.0 through 3.0.4 contain a bug in the handle_trailers function where rejected trailer headers (forbidden or undeclared) cause an infinite loop. When handle_trailers encounters such a trailer, three code paths (lines 520, 523, 526) recurse with the original buffer (rest) instead of advancing past the rejected header (Buffer(header_rest, 0)), causing decoder.decode_packet to re-parse the same header on every iteration. The resulting loop has no timeout or escape — the BEAM process permanently wedges at 100% CPU. Any application that calls ewe.read_body on chunked requests is affected, and this is exploitable by any unauthenticated remote client before control returns to application code, making an application-level workaround impossible. This issue is fixed in version 3.0.5.
| 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 |
ewe: Loop with Unreachable Exit Condition ('Infinite Loop')