CVE-2024-1638 Bluetooth characteristic LESC security requirement not enforced without additional flags
Attackers can read or write Bluetooth characteristics without encryption because the stack fails to enforce LE Secure Connections permissions unless additional flags are set.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-1638?
CVE-2024-1638 is a high-severity missing authorization vulnerability in Zephyrproject Zephyr, published on 19 Feb 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2024-1638?
It affects 1 product.
Products include Zephyrproject Zephyr.
How do I fix CVE-2024-1638?
No fix has been published for CVE-2024-1638 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2024-1638 being exploited?
There is no known exploitation of CVE-2024-1638 in the wild and no public exploit code.
Other vulnerabilities in Zephyrproject Zephyr
- CVE-2026-5067 Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key
- CVE-2022-3806 Bluetooth HCI Error Handling Double Free
- CVE-2017-14199 Memory corruption in getaddrinfo
- CVE-2018-1000800 Null dereference in n/a
- CVE-2021-3329 DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer
Sources
Also known as GHSA-p6f3-f63q-5mc2.