Description

When a fusefs file system implements extended attributes, the kernel may send a FUSE_LISTXATTR message to the userspace daemon to retrieve the list of extended attributes for a given file. The FUSE protocol requires the daemon to return a packed list of NUL-terminated strings. The fusefs kernel module calls strlen() on this daemon-supplied buffer without first verifying that the entire list is NUL-terminated. If a malicious daemon sends a non-NUL-terminated list, the fusefs kernel module may read beyond the end of one heap-allocated buffer and potentially write beyond the end of a second buffer. A malicious daemon could disclose up to 253 bytes of kernel heap memory, or it could inject up to 250 attacker-controlled bytes into unallocated kernel heap space.

Type de vulnérabilité

• CWE-122

Vecteur d'attaque

Complexité : LOW

Privilèges requis : HIGH

Interaction utilisateur : NONE

Impact

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

Recommandations

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