UBUNTU-CVE-2021-23133
A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.
02 / AFFECTED SOFTWARE
Affected packages
13 explicit affected versions
1 explicit affected versions
29 explicit affected versions
13 explicit affected versions
60 explicit affected versions
1 explicit affected versions
32 explicit affected versions
33 explicit affected versions
10 explicit affected versions
45 explicit affected versions
11 explicit affected versions
68 explicit affected versions
1 explicit affected versions
29 explicit affected versions
63 explicit affected versions
25 explicit affected versions
3 explicit affected versions
1 explicit affected versions
9 explicit affected versions
22 explicit affected versions
1 explicit affected versions
1 explicit affected versions
25 explicit affected versions
1 explicit affected versions
19 explicit affected versions
1 explicit affected versions
20 explicit affected versions
1 explicit affected versions
22 explicit affected versions
9 explicit affected versions
18 explicit affected versions
44 explicit affected versions
16 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
19 explicit affected versions
3 explicit affected versions
76 explicit affected versions
53 explicit affected versions
1 explicit affected versions
12 explicit affected versions
44 explicit affected versions
19 explicit affected versions
43 explicit affected versions
1 explicit affected versions
91 explicit affected versions
12 explicit affected versions
22 explicit affected versions
4 explicit affected versions
9 explicit affected versions
1 explicit affected versions
50 explicit affected versions
6 explicit affected versions
6 explicit affected versions
1 explicit affected versions
66 explicit affected versions
27 explicit affected versions
46 explicit affected versions
19 explicit affected versions
76 explicit affected versions
1 explicit affected versions
23 explicit affected versions
1 explicit affected versions
1 explicit affected versions
19 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
1 explicit affected versions
29 explicit affected versions
37 explicit affected versions
29 explicit affected versions
21 explicit affected versions
10 explicit affected versions
14 explicit affected versions
43 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=b166a20b07382b8bc1dcee2a448715c9c2c81b5b
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b166a20b07382b8bc1dcee2a448715c9c2c81b5b
- https://ubuntu.com/security/CVE-2021-23133
- https://ubuntu.com/security/notices/USN-4997-1
- https://ubuntu.com/security/notices/USN-4997-2
- https://ubuntu.com/security/notices/USN-4999-1
- https://ubuntu.com/security/notices/USN-5000-1
- https://ubuntu.com/security/notices/USN-5000-2
- https://ubuntu.com/security/notices/USN-5001-1
- https://ubuntu.com/security/notices/USN-5003-1
- https://www.cve.org/CVERecord?id=CVE-2021-23133
- https://www.openwall.com/lists/oss-security/2021/04/18/2