CVE-2022-50243 sctp: handle the error returned from sctp_auth_asoc_init_active_key
A use-after-free vulnerability in the Linux kernel SCTP implementation allows attackers to trigger crashes or potentially execute code via crafted network packets.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50243?
CVE-2022-50243 is a high-severity use after free vulnerability in Linux kernel, published on 15 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2022-50243?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50243?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-50243 being exploited?
There is no known exploitation of CVE-2022-50243 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50243, GHSA-2hwr-p3mh-h7f6, UBUNTU-CVE-2022-50243.