The btrfs_ioctl_clone function in fs/btrfs/ioctl.c in the Linux kernel before 2.6.35 allows local users to overwrite an append-only file via a (1) BTRFS_IOC_CLONE or (2) BTRFS_IOC_CLONE_RANGE ioctl call that specifies this file as a donor.
Severity
CVSS 3.1
7.1 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS
0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-31)