{"id":"CVE-2025-68183","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-68183","generatedAt":"2026-10-28T09:26:27.032Z","title":"In the Linux kernel, the following vulnerability has been resolved: ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr Currently when both IMA and EVM are in fix mode, the IMA signature will be reset to IMA hash if a program first…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr\n\nCurrently when both IMA and EVM are in fix mode, the IMA signature will\nbe reset to IMA hash if a program first stores IMA signature in\nsecurity.ima and then writes/removes some other security xattr for the\nfile.\n\nFor example, on Fedora, after booting the kernel with \"ima_appraise=fix\nevm=fix ima_policy=appraise_tcb\" and installing rpm-plugin-ima,\ninstalling/reinstalling a package will not make good reference IMA\nsignature generated. Instead IMA hash is generated,\n\n    # getfattr -m - -d -e hex /usr/bin/bash\n    # file: usr/bin/bash\n    security.ima=0x0404...\n\nThis happens because when setting security.selinux, the IMA_DIGSIG flag\nthat had been set early was cleared. As a result, IMA hash is generated\nwhen the file is closed.\n\nSimilarly, IMA signature can be cleared on file close after removing\nsecurity xattr like security.evm or setting/removing ACL.\n\nPrevent replacing the IMA file signature with a file hash, by preventing\nthe IMA_DIGSIG flag from being reset.\n\nHere's a minimal C reproducer which sets security.selinux as the last\nstep which can also replaced by removing security.evm or setting ACL,\n\n    #include <stdio.h>\n    #include <sys/xattr.h>\n    #include <fcntl.h>\n    #include <unistd.h>\n    #include <string.h>\n    #include <stdlib.h>\n\n    int main() {\n        const char* file_path = \"/usr/sbin/test_binary\";\n        const char* hex_string = \"030204d33204490066306402304\";\n        int length = strlen(hex_string);\n        char* ima_attr_value;\n        int fd;\n\n        fd = open(file_path, O_WRONLY|O_CREAT|O_EXCL, 0644);\n        if (fd == -1) {\n            perror(\"Error opening file\");\n            return 1;\n        }\n\n        ima_attr_value = (char*)malloc(length / 2 );\n        for (int i = 0, j = 0; i < length; i += 2, j++) {\n            sscanf(hex_string + i, \"%2hhx\", &ima_attr_value[j]);\n        }\n\n        if (fsetxattr(fd, \"security.ima\", ima_attr_value, length/2, 0) == -1) {\n            perror(\"Error setting extended attribute\");\n            close(fd);\n            return 1;\n        }\n\n        const char* selinux_value= \"system_u:object_r:bin_t:s0\";\n        if (fsetxattr(fd, \"security.selinux\", selinux_value, strlen(selinux_value), 0) == -1) {\n            perror(\"Error setting extended attribute\");\n            close(fd);\n            return 1;\n        }\n\n        close(fd);\n\n        return 0;\n    }","published":"2025-12-16T14:15:51.000Z","lastModified":"2026-10-15T22:19:10.000Z","status":"Deferred","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":[],"epss":{"score":0.00154,"percentile":0.04478,"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":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/02aa671c08a4834bef5166743a7b88686fbfa023","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/88b4cbcf6b041ae0f2fc8a34554a5b6a83a2b7cd","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d2993a7e98eb70c737c6f5365a190e79c72b8407","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/edd824eb45e4f7e05ad3ab090dab6dbdb79cd292","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-68183","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."}