Description

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a use-after-free vulnerability in sixel_encoder_encode_bytes() because sixel_frame_init() stores the caller-owned pixel buffer pointer directly in frame->pixels without making a defensive copy. When a resize operation is triggered, sixel_frame_convert_to_rgb888() unconditionally frees this caller-owned buffer and replaces it with a new internal allocation, leaving the caller with a dangling pointer. Any subsequent access to the original buffer by the caller constitutes a use-after-free, confirmed by AddressSanitizer. An attacker who controls incoming frames can trigger this bug repeatedly and predictably, resulting in a reliable crash with potential for code execution. This issue has been fixed in version 1.8.7-r1.

Type de vulnérabilité

• CWE-416

Vecteur d'attaque

Complexité : LOW

Privilèges requis : NONE

Interaction utilisateur : NONE

Impact

• Confidentialité : LOW
• Intégrité : LOW
• Disponibilité : HIGH

Recommandations

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