Buffer overflow in Cypress Cyw20735b1
CVE-2019-13916
An issue was discovered in Cypress (formerly Broadcom) WICED Studio 6.2 CYW20735B1 and CYW20819A1. As a Bluetooth Low Energy (BLE) packet is received, it is copied into a Heap (ThreadX Block) buffer. The buffer allocated in dhmulp_getRxBuffer is four bytes too small to hold the maximum of 255 bytes plus headers. It is possible to corrupt a pointer in the linked list holding the free buffers of the g_mm_BLEDeviceToHostPool Block pool. This pointer can be fully controlled by overflowing with 3 bytes of packet data and the first byte of the packet CRC checksum. The checksum can be freely chosen by adapting the packet data accordingly. An attacker might be able to allocate the overwritten address as a receive buffer resulting in a write-what-where condition. This is fixed in BT SDK2.4 and BT SDK2.45.
Vulnerability class: Buffer Overflow
EPSS: 0.012 (65.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Cypress Cyw20735b1
- Cypress Cyw20819a1
- Cypress Wiced_studio — versions 6.2
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Permissions Required, x_refsource_MISC, Vendor Advisory)
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2019-13916?
- CVE-2019-13916 is a high-severity vulnerability in Cypress Cyw20735b1, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2020-04-13.
- How severe is CVE-2019-13916?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2019-13916 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.