CVE-2023-53635
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: fix wrong ct->timeout value
(struct nf_conn)->timeout is an interval before the conntrack confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack: - Set by calling ctnetlink_change_timeout(). As a result, `nfct_time_stamp` was wrongly added to `ct->timeout` twice. - Get by calling ctnetlink_dump_timeout(). As a result, `nfct_time_stamp` was wrongly subtracted.
Call Trace: <TASK> dump_stack_lvl ctnetlink_dump_timeout __ctnetlink_glue_build ctnetlink_glue_build __nfqnl_enqueue_packet nf_queue nf_hook_slow ip_mc_output ? __pfx_ip_finish_output ip_send_skb ? __pfx_dst_output udp_send_skb udp_sendmsg ? __pfx_ip_generic_getfrag sock_sendmsg
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Separate the 2 cases in: - Setting `ct->timeout` in __nf_ct_set_timeout(). - Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the introduction of the nfnetlink_queue conntrack support, select a sufficiently old Fixes: tag for -stable kernel to pick up this fix.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.43%
- Percentil entre todas las CVEs puntuadas: 35
- Fecha de la puntuación: 5/10/2026
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).
Tecnologías afectadas (1)
CWE
- NVD-CWE-noinfo
Referencias
JSON original (NVD)
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: fix wrong ct->timeout value\n\n(struct nf_conn)->timeout is an interval before the conntrack\nconfirmed. After confirmed, it becomes a timestamp.\n\nIt is observed that timeout of an unconfirmed conntrack:\n- Set by calling ctnetlink_change_timeout(). As a result,\n `nfct_time_stamp` was wrongly added to `ct->timeout` twice.\n- Get by calling ctnetlink_dump_timeout(). As a result,\n `nfct_time_stamp` was wrongly subtracted.\n\nCall Trace:\n <TASK>\n dump_stack_lvl\n ctnetlink_dump_timeout\n __ctnetlink_glue_build\n ctnetlink_glue_build\n __nfqnl_enqueue_packet\n nf_queue\n nf_hook_slow\n ip_mc_output\n ? __pfx_ip_finish_output\n ip_send_skb\n ? __pfx_dst_output\n udp_send_skb\n udp_sendmsg\n ? __pfx_ip_generic_getfrag\n sock_sendmsg\n\nSeparate the 2 cases in:\n- Setting `ct->timeout` in __nf_ct_set_timeout().\n- Getting `ct->timeout` in ctnetlink_dump_timeout().\n\nPablo appends:\n\nUpdate ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is\nset on, otherwise conntrack creation via ctnetlink breaks.\n\nNote that the problem described in this patch occurs since the\nintroduction of the nfnetlink_queue conntrack support, select a\nsufficiently old Fixes: tag for -stable kernel to pick up this fix."
}
],
"lastModified": "2026-08-04T10:19:15.660",
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