CVE-2025-68183
Full vulnerability record from the local CVENow database.
Description
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 stores IMA signature in security.ima and then writes/removes some other security xattr for the file. For example, on Fedora, after booting the kernel with "ima_appraise=fix evm=fix ima_policy=appraise_tcb" and installing rpm-plugin-ima, installing/reinstalling a package will not make good reference IMA signature generated. Instead IMA hash is generated, # getfattr -m - -d -e hex /usr/bin/bash # file: usr/bin/bash security.ima=0x0404... This happens because when setting security.selinux, the IMA_DIGSIG flag that had been set early was cleared. As a result, IMA hash is generated when the file is closed. Similarly, IMA signature can be cleared on file close after removing security xattr like security.evm or setting/removing ACL. Prevent replacing the IMA file signature with a file hash, by preventing the IMA_DIGSIG flag from being reset. Here's a minimal C reproducer which sets security.selinux as the last step which can also replaced by removing security.evm or setting ACL, #include <stdio.h> #include <sys/xattr.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <stdlib.h> int main() { const char* file_path = "/usr/sbin/test_binary"; const char* hex_string = "030204d33204490066306402304"; int length = strlen(hex_string); char* ima_attr_value; int fd; fd = open(file_path, O_WRONLY|O_CREAT|O_EXCL, 0644); if (fd == -1) { perror("Error opening file"); return 1; } ima_attr_value = (char*)malloc(length / 2 ); for (int i = 0, j = 0; i < length; i += 2, j++) { sscanf(hex_string + i, "%2hhx", &ima_attr_value[j]); } if (fsetxattr(fd, "security.ima", ima_attr_value, length/2, 0) == -1) { perror("Error setting extended attribute"); close(fd); return 1; } const char* selinux_value= "system_u:object_r:bin_t:s0"; if (fsetxattr(fd, "security.selinux", selinux_value, strlen(selinux_value), 0) == -1) { perror("Error setting extended attribute"); close(fd); return 1; } close(fd); return 0; }
View original CVE JSON
{
"id": "CVE-2025-68183",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-12-16T14:15:50.880",
"lastModified": "2026-10-30T13:18:17.433",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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 }"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nima: no borrar el flag IMA_DIGSIG al establecer o eliminar un xattr que no es de IMA\n\nActualmente, cuando tanto IMA como EVM están en modo fix, la firma IMA se restablecerá al hash IMA si un programa primero almacena la firma IMA en security.ima y luego escribe/elimina algún otro xattr de seguridad para el archivo.\n\nPor ejemplo, en Fedora, después de arrancar el kernel con 'ima_appraise=fix evm=fix ima_policy=appraise_tcb' e instalar rpm-plugin-ima, instalar/reinstalar un paquete no generará una buena firma IMA de referencia. En su lugar, se genera un hash IMA,\n\n # getfattr -m - -d -e hex /usr/bin/bash\n # file: usr/bin/bash\n security.ima=0x0404...\n\nEsto sucede porque al establecer security.selinux, el flag IMA_DIGSIG que se había establecido previamente fue borrado. Como resultado, se genera un hash IMA cuando se cierra el archivo.\n\nDe manera similar, la firma IMA puede borrarse al cerrar el archivo después de eliminar un xattr de seguridad como security.evm o al establecer/eliminar una ACL.\n\nEvitar reemplazar la firma de archivo IMA con un hash de archivo, impidiendo que el flag IMA_DIGSIG se restablezca.\n\nAquí hay un reproductor mínimo en C que establece security.selinux como el último paso, que también puede ser reemplazado eliminando security.evm o estableciendo una 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 }"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"security/integrity/ima/ima_appraise.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "e3ccfe1ad7d895487977ef64eda3441d16c9851a",
"lessThan": "7d9ae9d4d45b28c18ca06ae047aabe09d9639643",
"versionType": "git",
"status": "affected"
},
{
"version": "e3ccfe1ad7d895487977ef64eda3441d16c9851a",
"lessThan": "d2993a7e98eb70c737c6f5365a190e79c72b8407",
"versionType": "git",
"status": "affected"
},
{
"version": "e3ccfe1ad7d895487977ef64eda3441d16c9851a",
"lessThan": "edd824eb45e4f7e05ad3ab090dab6dbdb79cd292",
"versionType": "git",
"status": "affected"
},
{
"version": "e3ccfe1ad7d895487977ef64eda3441d16c9851a",
"lessThan": "02aa671c08a4834bef5166743a7b88686fbfa023",
"versionType": "git",
"status": "affected"
},
{
"version": "e3ccfe1ad7d895487977ef64eda3441d16c9851a",
"lessThan": "88b4cbcf6b041ae0f2fc8a34554a5b6a83a2b7cd",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"security/integrity/ima/ima_appraise.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.14",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.14",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.117",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.58",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.8",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-15T21:59:57.175994Z",
"id": "CVE-2025-68183",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/02aa671c08a4834bef5166743a7b88686fbfa023",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7d9ae9d4d45b28c18ca06ae047aabe09d9639643",
"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"
}
]
}