CVE-2024-1638: Bluetooth characteristic LESC security requirement not enforced without additional flags
Description
The documentation specifies that the BT_GATT_PERM_READ_LESC and BT_GATT_PERM_WRITE_LESC defines for a Bluetooth characteristic: Attribute read/write permission with LE Secure Connection encryption. If set, requires that LE Secure Connections is used for read/write access, however this is only true when it is combined with other permissions, namely BT_GATT_PERM_READ_ENCRYPT/BT_GATT_PERM_READ_AUTHEN (for read) or BT_GATT_PERM_WRITE_ENCRYPT/BT_GATT_PERM_WRITE_AUTHEN (for write), if these additional permissions are not set (even in secure connections only mode) then the stack does not perform any permission checks on these characteristics and they can be freely written/read.
Classification
CVE ID: CVE-2024-1638
CVSS Base Severity: HIGH
CVSS Base Score: 8.2
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Problem Types
CWE-20 Improper Input ValidationAffected Products
Vendor: zephyrproject-rtos
Product: Zephyr
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.15% (probability of being exploited)
EPSS Percentile: 36.68% (scored less or equal to compared to others)
EPSS Date: 2025-05-23 (when was this score calculated)
Stakeholder-Specific Vulnerability Categorization (SSVC)
SSVC Exploitation: none
SSVC Technical Impact: partial
SSVC Automatable: true
References
https://nvd.nist.gov/vuln/detail/CVE-2024-1638https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p6f3-f63q-5mc2