Description

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode("xn--example-.com") incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".

Type de vulnérabilité

• CWE-1289

Vecteur d'attaque

Complexité : LOW

Privilèges requis : LOW

Interaction utilisateur : NONE

Impact

• Confidentialité : HIGH
• Intégrité : HIGH
• Disponibilité : NONE

Recommandations

Appliquer les correctifs de sécurité fournis par le vendeur dès que possible.