CVE-2018-18056

CVE-2018-18056 is a medium-severity vulnerability in Ti Tm4c123 Firmware with a CVSS 3.x base score of 4.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Description

An issue was discovered in the Texas Instruments (TI) TM4C, MSP432E and MSP432P microcontroller series. The eXecute-Only-Memory (XOM) implementation prevents code read-outs on protected memory by generating bus faults. However, single-stepping and using breakpoints is allowed in XOM-protected flash memory. As a consequence, it is possible to execute single instructions with arbitrary system states (e.g., registers, status flags, and SRAM content) and observe the state changes produced by the unknown instruction. An attacker could exploit this vulnerability by executing protected and unknown instructions with specific system states and observing the state changes. Based on the gathered information, it is possible to reverse-engineer the executed instructions. The processor acts as a kind of "instruction oracle."

Frequently asked questions

What is CVE-2018-18056?
An issue was discovered in the Texas Instruments (TI) TM4C, MSP432E and MSP432P microcontroller series. The eXecute-Only-Memory (XOM) implementation prevents code read-outs on protected memory by generating bus faults. However, single-stepping and using breakpoints is allowed in XOM-protected flash memory. As a consequence, it is possible to execute single instructions with arbitrary system states (e.g., registers, status flags, and SRAM content) and observe the state changes produced by the unknown instruction. An attacker could exploit this vulnerability by executing protected and unknown instructions with specific system states and observing the state changes. Based on the gathered information, it is possible to reverse-engineer the executed instructions. The processor acts as a kind of "instruction oracle."
How severe is CVE-2018-18056?
CVE-2018-18056 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-18056 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-18056?
CVE-2018-18056 primarily affects Ti Tm4c123 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-18056?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-18056 published?
CVE-2018-18056 was published on 2019-08-20 and last updated on 2026-06-17.

References

Affected products (2)

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