{"id":"CVE-2018-18056","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-18056","generatedAt":"2026-10-28T21:28:39.254Z","title":"The eXecute-Only-Memory (XOM) implementation prevents code read-outs on protected memory by generating bus faults.","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.\"","published":"2019-08-20T17:15:11.000Z","lastModified":"2026-06-17T01:46:43.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":4.6,"severity":"MEDIUM","vector":"CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-200"],"affected":["ti/tm4c123 firmware","ti/tm4c129 firmware"],"epss":{"score":0.00405,"percentile":0.34635,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://www.usenix.org/conference/woot19/presentation/schink","tags":["Technical Description","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.usenix.org/system/files/woot19-paper_schink.pdf","tags":["Technical Description","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.usenix.org/conference/woot19/presentation/schink","tags":["Technical Description","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.usenix.org/system/files/woot19-paper_schink.pdf","tags":["Technical Description","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-18056","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}