CVE-2018-18056
The eXecute-Only-Memory (XOM) implementation prevents code read-outs on protected memory by generating bus faults.
Does this matter?
Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own.
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 3.0
- 4.6 MEDIUMCVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.40% probability · 35th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- ti/tm4c123 firmware · ti/tm4c129 firmware
- Source
- cve@mitre.org
EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://www.usenix.org/conference/woot19/presentation/schinkTechnical Description, Third Party Advisory
- https://www.usenix.org/system/files/woot19-paper_schink.pdfTechnical Description, Third Party Advisory
- https://www.usenix.org/conference/woot19/presentation/schinkTechnical Description, Third Party Advisory
- https://www.usenix.org/system/files/woot19-paper_schink.pdfTechnical Description, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.