CVE-2024-1638: zephyr Input Validation Flaw

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.

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CVSS v3.1 Score

8.2

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Weakness Type (CWE)

CWE-20 Improper Input Validation

Affected Products

Vendor	Product	Versions
zephyrproject	zephyr	< 3.5.0

References

Advisories & Patches

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p6f3-f63q-5mc2 https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p6f3-f63q-5mc2

Exploits

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p6f3-f63q-5mc2 https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p6f3-f63q-5mc2

Frequently Asked Questions

What is CVE-2024-1638? +

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. It has a CVSS v3.1 base score of 8.2 (HIGH).

How severe is CVE-2024-1638? +

CVE-2024-1638 has a CVSS v3.1 score of 8.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2024-1638? +

CVE-2024-1638 affects products from zephyrproject, specifically: zephyr. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-1638? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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