CVE-2021-23133

Linux Kernel sctp_destroy_sock race condition

HIGH
7
CVSS Score
Published: April 22, 2021 at 06:00 PM UTC
Updated: July 30, 2026 at 07:59 PM UTC
25 products affected across 6 vendorsLinux KernelDebian LinuxFedora

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Severity
HIGH7
Exploit prediction
EPSS 0.5%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.4.2694.10 ≤ v < 4.14.2334.15 ≤ v < 4.19.1914.20 ≤ v < 5.4.1194.5 ≤ v < 4.9.2695.11 ≤ v < 5.11.215.12 ≤ v < 5.12.45.5 ≤ v < 5.10.37
Affected range stops below 4.14.233, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.19.191, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.4.269, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.9.269, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.10.37, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.11.21, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.12.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.4.119, so it looks safe — our inference, not a vendor statement
All versions
All versions
netapp-h300e (same device)
All versions
netapp-h300s (same device)
All versions
netapp-h410c (same device)
All versions
netapp-h410s (same device)
All versions
netapp-h500e (same device)

References (12)

Mailing Listx_refsource_MLISTPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/10/1
Mailing Listx_refsource_MLISTPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/10/2
Mailing Listx_refsource_MLISTPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/10/3
Mailing Listx_refsource_MLISTPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/10/4
Mailing Listx_refsource_MLISTMitigationThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
Mailing Listx_refsource_MLISTMitigationThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

CVSS

Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-362

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