An issue was discovered in Espressif ESP-IDF 2.x and 3.x before 3.0.6 and 3.1.x before 3.1.1. Insufficient validation of input data in the 2nd stage bootloader allows a physically proximate attacker to bypass secure boot checks and execute arbitrary code, by crafting an application binary that overwrites a bootloader code segment in process_segment in components/bootloader_support/src/esp_image_format.c. The attack is effective when the flash encryption feature is not enabled, or if the attacker finds a different vulnerability that allows them to write this binary to flash memory.

The PV superpage functionality in arch/x86/mm.c in Xen 3.4.0, 3.4.1, and 4.1.x through 4.6.x allows local PV guests to obtain sensitive information, cause a denial of service, gain privileges, or have unspecified other impact via a crafted page identifier (MFN) to the (1) MMUEXT_MARK_SUPER or (2) MMUEXT_UNMARK_SUPER sub-op in the HYPERVISOR_mmuext_op hypercall or (3) unknown vectors related to page table updates.

A version of the SymEvent Driver that shipped with Symantec Endpoint Protection 12.1 RU6 MP6 and earlier fails to properly sanitize logged-in user input. SEP 14.0 and later are not impacted by this issue. A non-admin user would need to be able to save an executable file to disk and then be able to successfully run that file. If properly constructed, the file could access the driver interface and potentially manipulate certain system calls. On all 32-bit systems and in most cases on 64-bit systems, this will result in a denial of service that will crash the system. In very narrow circumstances, and on 64-bit systems only, this could allow the user to run arbitrary code on the local machine with kernel-level privileges. This could result in a non-privileged user gaining privileged access on the local machine.