CVE-2025-40241
In the Linux kernel, the following vulnerability has been resolved:
erofs: fix crafted invalid cases for encoded extents
Robert recently reported two corrupted images that can cause system crashes, which are related to the new encoded extents introduced in Linux 6.15:
Detalles técnicos trazas, registros y código del informe original
- The first one [1] has plen != 0 (e.g. plen == 0x2000000) but
(plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent
special extents such as sparse extents (!EROFS_MAP_MAPPED), but
previously only plen == 0 was handled;
- The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000,
then "cur [0xfffffffffffff000] += bvec.bv_len [0x1000]" in
"} while ((cur += bvec.bv_len) < end);" wraps around, causing an
out-of-bound access of pcl->compressed_bvecs[] in
z_erofs_submit_queue(). EROFS only supports 48-bit physical block
addresses (up to 1EiB for 4k blocks), so add a sanity check to
enforce this.CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.14%
- Percentil entre todas las CVEs puntuadas: 3
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact75 % - Impacto secundario
T1565.001Stored Data Manipulationimpact60 %
AV:L/PR:L indica escalada local; el manejo de extents corruptos causa DoS/crash del sistema (T1499.004) y potencial corrupción de datos en memoria comprimida (T1565.001).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2025-40241",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1d191b4ca51d73699cb127386b95ac152af2b930",
"lessThan": "00d8fe0b72f4ca0a983abced36aad2160038c421",
"versionType": "git"
},
{
"status": "affected",
"version": "1d191b4ca51d73699cb127386b95ac152af2b930",
"lessThan": "a429b76114aaca3ef1aff4cd469dcf025431bd11",
"versionType": "git"
}
],
"programFiles": [
"fs/erofs/zmap.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.17.6",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/erofs/zmap.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-04T16:16:17.250",
"references": [
{
"url": "https://git.kernel.org/stable/c/00d8fe0b72f4ca0a983abced36aad2160038c421",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a429b76114aaca3ef1aff4cd469dcf025431bd11",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix crafted invalid cases for encoded extents\n\nRobert recently reported two corrupted images that can cause system\ncrashes, which are related to the new encoded extents introduced\nin Linux 6.15:\n\n - The first one [1] has plen != 0 (e.g. plen == 0x2000000) but\n (plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent\n special extents such as sparse extents (!EROFS_MAP_MAPPED), but\n previously only plen == 0 was handled;\n\n - The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000,\n then \"cur [0xfffffffffffff000] += bvec.bv_len [0x1000]\" in\n \"} while ((cur += bvec.bv_len) < end);\" wraps around, causing an\n out-of-bound access of pcl->compressed_bvecs[] in\n z_erofs_submit_queue(). EROFS only supports 48-bit physical block\n addresses (up to 1EiB for 4k blocks), so add a sanity check to\n enforce this."
}
],
"lastModified": "2026-07-30T06:24:19.430",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}