CVE-2018-18056 — MEDIUM (4.6)

Vulnerability 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."

CVSS Score

4.6

MEDIUM

CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

PHYSICAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Affected Products

Vendor	Product	Versions
Ti	Tm4C123 Firmware	-
Ti	Tm4C123	-
Ti	Tm4C129 Firmware	-
Ti	Tm4C129	-

Related Weaknesses (CWE)

CWE-200

References

https://www.usenix.org/conference/woot19/presentation/schinkTechnical DescriptionThird Party Advisory
https://www.usenix.org/system/files/woot19-paper_schink.pdfTechnical DescriptionThird Party Advisory
https://www.usenix.org/conference/woot19/presentation/schinkTechnical DescriptionThird Party Advisory
https://www.usenix.org/system/files/woot19-paper_schink.pdfTechnical DescriptionThird Party Advisory

FAQ

What is CVE-2018-18056?

CVE-2018-18056 is a vulnerability with a CVSS score of 4.6 (MEDIUM). 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 gene...

How severe is CVE-2018-18056?

CVE-2018-18056 has been rated MEDIUM with a CVSS base score of 4.6/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2018-18056?

Check the references section above for vendor advisories and patch information. Affected products include: Ti Tm4C123 Firmware, Ti Tm4C123, Ti Tm4C129 Firmware, Ti Tm4C129.