Zephyr Project up to 4.3.1/4.4.x Simulated EEPROM Driver eeprom_simulator.c eeprom_range_is_valid offset integer overflow

Summaryinfo

A vulnerability was found in Zephyr Project Zephyr up to 4.3.1/4.4.x and classified as very critical. The affected element is the function eeprom_range_is_valid of the file drivers/eeprom/eeprom_simulator.c of the component Simulated EEPROM Driver. Executing a manipulation of the argument offset can lead to integer overflow. This vulnerability is handled as CVE-2026-90833. It is possible to launch the attack on the local host. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Zephyr Project Zephyr up to 4.3.1/4.4.x. It has been declared as very critical. This vulnerability affects the function eeprom_range_is_valid of the file drivers/eeprom/eeprom_simulator.c of the component Simulated EEPROM Driver. The manipulation of the argument offset with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

The simulated EEPROM driver validated access ranges in eeprom_range_is_valid() (drivers/eeprom/eeprom_simulator.c) with a single test, (offset + len) <= config->size. Because offset is a signed off_t and len an unsigned size_t of the same rank, the addition is evaluated in unsigned arithmetic: a negative offset combined with a compensating len wraps the sum back into the accepted range. eeprom_sim_read() and eeprom_sim_write() then memcpy() through the EEPROM(addr) macro, which is plain pointer arithmetic on the driver's static mock_eeprom array, so the copy addresses memory located before that array. eeprom_read() and eeprom_write() are __syscall entry points, and their verification handlers in drivers/eeprom/eeprom_handlers.c check only the device object and the caller's own data buffer (K_SYSCALL_MEMORY_READ/K_SYSCALL_MEMORY_WRITE) — the offset argument is passed to the driver unvalidated. With CONFIG_USERSPACE=y, a CONFIG_EEPROM_SIMULATOR device instance, and the device object granted to a user thread (the usage the in-tree tests/drivers/eeprom/api suite exercises from ZTEST_USER threads), an unprivileged thread could supply a negative offset and have the kernel perform the copy on its behalf. The result is an out-of-bounds read of kernel .bss returned into the caller's buffer and, via the write path, an out-of-bounds write of caller-supplied bytes over kernel memory preceding mock_eeprom. Both the start address and the length of the affected span are attacker-selected, so the primitive is sufficient to corrupt adjacent kernel state and escape the user-mode sandbox. Exposure is limited to builds that instantiate the simulated EEPROM (status = "okay" by default on qemu_x86 and native_sim, otherwise added by a devicetree overlay) together with userspace isolation. The fix rejects negative offsets and performs the remaining bound check without overflow.

The advisory is available at github.com. This vulnerability was named CVE-2026-90833 since 09/13/2026. The exploitation appears to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD at the moment (estimation calculated on 11/10/2026).

Upgrading to version 4.3.2 or 4.5.0 eliminates this vulnerability.

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Productinfo

Type

• Project Management Software

Vendor

• Zephyr Project

Name

• Zephyr

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.3.0
• 4.3.1
• 4.4

CPE 2.3info

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CPE 2.2info

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