{"id":"CVE-2021-47055","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmtd: require write permissions for locking and badblock ioctls\n\nMEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmtd: require write permissions for locking and badblock ioctls\n\nMEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require\nwrite permission. Depending on the h…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","cwe":["CWE-667"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.4.233, < 4.4.269","linux_kernel >= 4.9.233, < 4.9.269","linux_kernel >= 4.14.194, < 4.14.233","linux_kernel >= 4.19.139, < 4.19.191","linux_kernel >= 5.4.58, < 5.4.119","linux_kernel >= 5.9, < 5.10.37","linux_kernel >= 5.11, < 5.11.21","linux_kernel >= 5.12, < 5.12.4"],"patched":["linux_kernel 5.12.4"],"published":"2024-02-29","updated":"2026-08-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-47055","references":[{"url":"https://git.kernel.org/stable/c/077259f5e777c3c8821f6b41dee709fcda27306b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1e97743fd180981bef5f01402342bb54bf1c6366","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5880afefe0cb9b2d5e801816acd58bfe91a96981","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/75ed985bd6c8ac1d4e673e93ea9d96c9908c1d37","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7b6552719c0ccbbea29dde4be141da54fdb5877e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9625b00cac6630479c0ff4b9fafa88bee636e1f0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a08799d3e8c8088640956237c183f83463c39668","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f4d28d8b9b0e7c4ae04214b8d7e0b0466ec6bcaf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f73b29819c6314c0ba8b7d5892dfb03487424bee","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/077259f5e777c3c8821f6b41dee709fcda27306b","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/1e97743fd180981bef5f01402342bb54bf1c6366","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/5880afefe0cb9b2d5e801816acd58bfe91a96981","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/75ed985bd6c8ac1d4e673e93ea9d96c9908c1d37","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/7b6552719c0ccbbea29dde4be141da54fdb5877e","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/9625b00cac6630479c0ff4b9fafa88bee636e1f0","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a08799d3e8c8088640956237c183f83463c39668","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/f4d28d8b9b0e7c4ae04214b8d7e0b0466ec6bcaf","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/f73b29819c6314c0ba8b7d5892dfb03487424bee","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00197,"epssPercentile":0.09675,"ingestedAt":"2026-08-04T10:39:39.745Z","slug":"CVE-2021-47055","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmtd: require write permissions for locking and badblock ioctls\n\nMEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require\nwrite permission. Depending on the hardware MEMLOCK might even be\nwrite-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK\nis always write-once.\n\nMEMSETBADBLOCK modifies the bad block table.\n\n## Affected\n\n- `linux_kernel >= 4.4.233, < 4.4.269`\n- `linux_kernel >= 4.9.233, < 4.9.269`\n- `linux_kernel >= 4.14.194, < 4.14.233`\n- `linux_kernel >= 4.19.139, < 4.19.191`\n- `linux_kernel >= 5.4.58, < 5.4.119`\n- `linux_kernel >= 5.9, < 5.10.37`\n- `linux_kernel >= 5.11, < 5.11.21`\n- `linux_kernel >= 5.12, < 5.12.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.12.4`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}