--- id: CVE-2021-23133 title: >- 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 summary: >- 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(s… severity: medium cvss: 6.7 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H' cwe: - CWE-362 - CWE-362 vendor: netapp product: cloud_backup affected: - linux_kernel < 4.4.269 - 'linux_kernel >= 4.5, < 4.9.269' - 'linux_kernel >= 4.10, < 4.14.233' - 'linux_kernel >= 4.15, < 4.19.191' - 'linux_kernel >= 4.20, < 5.4.119' - 'linux_kernel >= 5.5, < 5.10.37' - 'linux_kernel >= 5.11, < 5.11.21' - 'linux_kernel >= 5.12, < 5.12.4' - fedora = 32 - fedora = 33 - fedora = 34 - debian_linux = 9.0 - cloud_backup - solidfire_&_hci_management_node - brocade_fabric_operating_system - h410c_firmware - h300s_firmware - h500s_firmware - h700s_firmware - h300e_firmware - h500e_firmware - h700e_firmware - h410s_firmware - solidfire_baseboard_management_controller_firmware patched: - linux_kernel 5.12.4 published: '2021-04-22' updated: '2026-07-30' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-23133' references: - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/1' label: psirt@paloaltonetworks.com - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/2' label: psirt@paloaltonetworks.com - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/3' label: psirt@paloaltonetworks.com - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/4' label: psirt@paloaltonetworks.com - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b166a20b07382b8bc1dcee2a448715c9c2c81b5b label: psirt@paloaltonetworks.com - url: 'https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html' label: psirt@paloaltonetworks.com - url: 'https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html' label: psirt@paloaltonetworks.com - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CUX2CA63453G34C6KYVBLJXJXEARZI2X/ label: psirt@paloaltonetworks.com - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAEQ3H6HKNO6KUCGRZVYSFSAGEUX23JL/ label: psirt@paloaltonetworks.com - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XZASHZVCOFJ4VU2I3BN5W5EPHWJQ7QWX/ label: psirt@paloaltonetworks.com - url: 'https://security.netapp.com/advisory/ntap-20210611-0008/' label: psirt@paloaltonetworks.com - url: 'https://www.openwall.com/lists/oss-security/2021/04/18/2' label: psirt@paloaltonetworks.com - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/1' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/2' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/3' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.openwall.com/lists/oss-security/2021/05/10/4' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b166a20b07382b8bc1dcee2a448715c9c2c81b5b label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CUX2CA63453G34C6KYVBLJXJXEARZI2X/ label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAEQ3H6HKNO6KUCGRZVYSFSAGEUX23JL/ label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XZASHZVCOFJ4VU2I3BN5W5EPHWJQ7QWX/ label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.netapp.com/advisory/ntap-20210611-0008/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.openwall.com/lists/oss-security/2021/04/18/2' label: af854a3a-2127-422b-91ae-364da2661108 tags: - nvd epss: 0.00475 epssPercentile: 0.38439 ingestedAt: '2026-07-30T19:55:34.832Z' --- ## Overview 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. ## Affected - `linux_kernel < 4.4.269` - `linux_kernel >= 4.5, < 4.9.269` - `linux_kernel >= 4.10, < 4.14.233` - `linux_kernel >= 4.15, < 4.19.191` - `linux_kernel >= 4.20, < 5.4.119` - `linux_kernel >= 5.5, < 5.10.37` - `linux_kernel >= 5.11, < 5.11.21` - `linux_kernel >= 5.12, < 5.12.4` - `fedora = 32` - `fedora = 33` - `fedora = 34` - `debian_linux = 9.0` - `cloud_backup` - `solidfire_&_hci_management_node` - `brocade_fabric_operating_system` - `h410c_firmware` - `h300s_firmware` - `h500s_firmware` - `h700s_firmware` - `h300e_firmware` - `h500e_firmware` - `h700e_firmware` - `h410s_firmware` - `solidfire_baseboard_management_controller_firmware` ## Remediation Upgrade past the affected range: - `linux_kernel 5.12.4`