CVE-2025-40304
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds
Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if the Y position is off-screen and clip image height to screen boundary. Break from the rendering loop if the X position is off-screen. When clipping image width to fit the screen, update the character count to match the clipped width to prevent buffer size mismatches.
Without the character count update, bit_putcs_aligned and bit_putcs_unaligned receive mismatched parameters where the buffer is allocated for the clipped width but cnt reflects the original larger count, causing out-of-bounds writes.
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
T1005Data from Local Systemcollection75 % - Impacto secundario
T1499.004Application or System Exploitationimpact70 %
Vulnerabilidad local (AV:L/PR:L) sin interacción que permite escritura fuera de límites en framebuffer, causando lectura/corrupción de memoria y potencial DoS del kernel.
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
- https://git.kernel.org/stable/c/15ba9acafb0517f8359ca30002c189a68ddbb939
- https://git.kernel.org/stable/c/1943b69e87b0ab35032d47de0a7fca9a3d1d6fc1
- https://git.kernel.org/stable/c/2d1359e11674ed4274934eac8a71877ae5ae7bbb
- https://git.kernel.org/stable/c/3637d34b35b287ab830e66048841ace404382b67
- https://git.kernel.org/stable/c/86df8ade88d290725554cefd03101ecd0fbd3752
- https://git.kernel.org/stable/c/996bfaa7372d6718b6d860bdf78f6618e850c702
- https://git.kernel.org/stable/c/ebc0730b490c7f27340b1222e01dd106e820320d
- https://git.kernel.org/stable/c/f0982400648a3e00580253e0c48e991f34d2684c
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-40304",
"cveTags": [],
"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-40304",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-06-16T19:54:32.739808Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
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"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
}
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"affected": [
{
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"affectedData": [
{
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},
{
"status": "unaffected",
"version": "5.4.302",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.247",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "5.15.197",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "6.1.159",
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},
{
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{
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{
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},
{
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"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
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],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-08T01:16:02.567",
"references": [
{
"url": "https://git.kernel.org/stable/c/15ba9acafb0517f8359ca30002c189a68ddbb939",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/996bfaa7372d6718b6d860bdf78f6618e850c702",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ebc0730b490c7f27340b1222e01dd106e820320d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f0982400648a3e00580253e0c48e991f34d2684c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds\n\nAdd bounds checking to prevent writes past framebuffer boundaries when\nrendering text near screen edges. Return early if the Y position is off-screen\nand clip image height to screen boundary. Break from the rendering loop if the\nX position is off-screen. When clipping image width to fit the screen, update\nthe character count to match the clipped width to prevent buffer size\nmismatches.\n\nWithout the character count update, bit_putcs_aligned and bit_putcs_unaligned\nreceive mismatched parameters where the buffer is allocated for the clipped\nwidth but cnt reflects the original larger count, causing out-of-bounds writes."
}
],
"lastModified": "2026-07-30T06:24:27.590",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}