libfsapfs through 20260921 contains an integer underflow in libfsapfs_key_encrypted_key_read_data() that allows attackers to trigger heap out-of-bounds reads via crafted KEK attributes. Attackers can supply a crafted encrypted APFS image with malformed HMAC or wrapped KEK attribute lengths to crash fsapfsinfo, pyfsapfs, dfVFS or plaso and read adjacent heap memory before password checks.
https://hackmd.io/@haind-pwn/libfsapfs-key-encrypted-key-attribute-oob-read
Published: 2026-10-15
Updated: 2026-10-16
Base Score: 5.6
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:C
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Severity: Medium
Base Score: 6.9
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.002