CVE-2022-50243: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: handle the error returned from sctp_auth_asoc_init_active_key When it returns an error from sctp_auth_asoc_init_active_key(), the active_key is actually not updated. The old sh_key will be freeed while it's still used as active key in asoc. Then an use-after-free will be triggered when sending patckets, as found by syzbot: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:132 [inline] sctp_sendmsg_to_asoc+0xbd5/0x1a20 net/sctp/socket.c:1863 sctp_sendmsg+0x1053/0x1d50 net/sctp/socket.c:2025 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 This patch is to fix it by not replacing the sh_key when it returns errors from sctp_auth_asoc_init_active_key() in sctp_auth_set_key(). For sctp_auth_set_active_key(), old active_key_id will be set back to asoc->active_key_id when the same thing happens.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.19.199 — 4.19.262
linux	linux_kernel	5.4.136 — 5.4.220
linux	linux_kernel	5.10.54 — 5.10.150
linux	linux_kernel	5.13.6 — 5.14
linux	linux_kernel	5.14.1 — 5.15.75
linux	linux_kernel	5.16 — 5.19.17
linux	linux_kernel	6.0 — 6.0.3
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/022152aaebe116a25c39818a07e175a8cd3c1e11 https://git.kernel.org/stable/c/0f90099d18e3abdc01babf686f41f63fe04939c1 https://git.kernel.org/stable/c/19d636b663e0e92951bba5fced929ca7fd25c552 https://git.kernel.org/stable/c/382ff44716603a54f5fd238ddec6a2468e217612 https://git.kernel.org/stable/c/3b0fcf5e29c0940e1169ce9c44f73edd98bdf12d https://git.kernel.org/stable/c/b8fa99a3a11bdd77fef6b4a97f1021eb30b5ba40 https://git.kernel.org/stable/c/f65955340e0044f5c41ac799a01698ac7dee8a4e

Frequently Asked Questions

What is CVE-2022-50243? +

In the Linux kernel, the following vulnerability has been resolved: sctp: handle the error returned from sctp_auth_asoc_init_active_key When it returns an error from sctp_auth_asoc_init_active_key(), the active_key is actually not updated. The old sh_key will be freeed while it's still used as active key in asoc. Then an use-after-free will be triggered when sending patckets, as found by syzbot: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:132 [inline] sctp_sendmsg_to_asoc+0xbd5/0x1a20 net/sctp/socket.c:1863 sctp_sendmsg+0x1053/0x1d50 net/sctp/socket.c:2025 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 This patch is to fix it by not replacing the sh_key when it returns errors from sctp_auth_asoc_init_active_key() in sctp_auth_set_key(). For sctp_auth_set_active_key(), old active_key_id will be set back to asoc->active_key_id when the same thing happens. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2022-50243? +

CVE-2022-50243 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2022-50243? +

CVE-2022-50243 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2022-50243? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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