CVE-2026-43027
Estado: ModificadaAlta (7.8)—
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_helper: pass helper to expect cleanup
nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the helper pointer as the data argument, so expect_iter_me() never matches any expectation and all of them survive the cleanup.
After unregister returns, nfnl_cthelper_del() frees the helper object immediately. Subsequent expectation dumps or packet-driven init_conntrack() calls then dereference the freed exp->helper, causing a use-after-free.
Leer descripción completaMostrar menos
Pass the actual helper pointer so expectations referencing it are properly destroyed before the helper object is freed.
Detalles técnicos trazas, registros y código del informe original
BUG: KASAN: slab-use-after-free in string+0x38f/0x430 Read of size 1 at addr ffff888003b14d20 by task poc/103 Call Trace: string+0x38f/0x430 vsnprintf+0x3cc/0x1170 seq_printf+0x17a/0x240 exp_seq_show+0x2e5/0x560 seq_read_iter+0x419/0x1280 proc_reg_read+0x1ac/0x270 vfs_read+0x179/0x930 ksys_read+0xef/0x1c0 Freed by task 103: The buggy address is located 32 bytes inside of freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)
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: 0.18%
- Percentil entre todas las CVEs puntuadas: 7
- 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
T1059Command and Scripting Interpreterexecution45 % - Impacto secundario
T1499.004Application or System Exploitationimpact60 %
AV:L + PR:L sin UI sugiere escalada local (T1068). UAF en kernel permite lectura/corrupción de memoria; pista menciona T1059 pero el texto principal describe crash/DoS en proc_read, no ejecución clara.
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)
CWE
- CWE-416
Referencias
- https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a
- https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be
- https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6
- https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1
- https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3
- https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965
- https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65
- https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
JSON original (NVD)
Mostrar
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"descriptions": [
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_helper: pass helper to expect cleanup\n\nnf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()\nto remove expectations belonging to the helper being unregistered.\nHowever, it passes NULL instead of the helper pointer as the data\nargument, so expect_iter_me() never matches any expectation and all\nof them survive the cleanup.\n\nAfter unregister returns, nfnl_cthelper_del() frees the helper\nobject immediately. Subsequent expectation dumps or packet-driven\ninit_conntrack() calls then dereference the freed exp->helper,\ncausing a use-after-free.\n\nPass the actual helper pointer so expectations referencing it are\nproperly destroyed before the helper object is freed.\n\n BUG: KASAN: slab-use-after-free in string+0x38f/0x430\n Read of size 1 at addr ffff888003b14d20 by task poc/103\n Call Trace:\n string+0x38f/0x430\n vsnprintf+0x3cc/0x1170\n seq_printf+0x17a/0x240\n exp_seq_show+0x2e5/0x560\n seq_read_iter+0x419/0x1280\n proc_reg_read+0x1ac/0x270\n vfs_read+0x179/0x930\n ksys_read+0xef/0x1c0\n Freed by task 103:\n The buggy address is located 32 bytes inside of\n freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)"
}
],
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