Описание
In the Linux kernel, the following vulnerability has been resolved:
tcp: challenge ACK for non-exact RST in SYN-RECEIVED
The SYN-RECEIVED request-socket path in tcp_check_req() accepts an
in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A
non-exact RST therefore removes the request instead of eliciting a
challenge ACK.
RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in
SYN-RECEIVED: an exact RST resets the connection, while a non-exact
in-window RST must trigger a challenge ACK and be dropped.
Apply that check before the ACK-field validation, following the RFC
sequence-number, RST, then ACK processing order. Factor the per-netns
challenge ACK quota out of tcp_send_challenge_ack() so request sockets
can share it. Use the request socket's send_ack() callback and its own
out-of-window ACK timestamp to send and rate-limit the response.
A flaw was found in the Linux kernel's handling of TCP (Transmission Control Protocol) connections. A remote attacker could send a specially crafted TCP Reset (RST) packet during the SYN-RECEIVED state. This could cause the system to prematurely remove connection requests instead of issuing a challenge acknowledgment (ACK), potentially leading to a denial of service (DoS) by disrupting the establishment of new network connections.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 8 | kernel | Affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux for NVIDIA 26 | kernel | Out of support scope | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Fix deferred |
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Дополнительная информация
Статус:
EPSS
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: tcp: challenge ACK for non-exact RST in SYN-RECEIVED The SYN-RECEIVED request-socket path in tcp_check_req() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request instead of eliciting a challenge ACK. RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in SYN-RECEIVED: an exact RST resets the connection, while a non-exact in-window RST must trigger a challenge ACK and be dropped. Apply that check before the ACK-field validation, following the RFC sequence-number, RST, then ACK processing order. Factor the per-netns challenge ACK quota out of tcp_send_challenge_ack() so request sockets can share it. Use the request socket's send_ack() callback and its own out-of-window ACK timestamp to send and rate-limit the response.
In the Linux kernel, the following vulnerability has been resolved: tcp: challenge ACK for non-exact RST in SYN-RECEIVED The SYN-RECEIVED request-socket path in tcp_check_req() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request instead of eliciting a challenge ACK. RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in SYN-RECEIVED: an exact RST resets the connection, while a non-exact in-window RST must trigger a challenge ACK and be dropped. Apply that check before the ACK-field validation, following the RFC sequence-number, RST, then ACK processing order. Factor the per-netns challenge ACK quota out of tcp_send_challenge_ack() so request sockets can share it. Use the request socket's send_ack() callback and its own out-of-window ACK timestamp to send and rate-limit the response.
In the Linux kernel, the following vulnerability has been resolved: t ...
In the Linux kernel, the following vulnerability has been resolved: tcp: challenge ACK for non-exact RST in SYN-RECEIVED The SYN-RECEIVED request-socket path in tcp_check_req() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request instead of eliciting a challenge ACK. RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in SYN-RECEIVED: an exact RST resets the connection, while a non-exact in-window RST must trigger a challenge ACK and be dropped. Apply that check before the ACK-field validation, following the RFC sequence-number, RST, then ACK processing order. Factor the per-netns challenge ACK quota out of tcp_send_challenge_ack() so request sockets can share it. Use the request socket's send_ack() callback and its own out-of-window ACK timestamp to send and rate-limit the response.
EPSS
7 High
CVSS3