UBUNTU-CVE-2021-23133

    Dashboard / Vulnerabilities / UBUNTU-CVE-2021-23133

    UBUNTU-CVE-2021-23133

    Published: 22 Apr 2021Last Modified: 9 Sept 2026
    Upstream:
    CVE-2021-23133
    Aliases:
    USN-4997-1
    USN-4997-2
    USN-4999-1

    Summary:

    Details: 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.

    References: https://ubuntu.com/security/CVE-2021-23133, 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://www.openwall.com/lists/oss-security/2021/04/18/2, https://ubuntu.com/security/notices/USN-4997-1, https://ubuntu.com/security/notices/USN-4999-1, https://ubuntu.com/security/notices/USN-5000-1, https://ubuntu.com/security/notices/USN-5001-1, https://ubuntu.com/security/notices/USN-5003-1, https://ubuntu.com/security/notices/USN-5000-2, https://ubuntu.com/security/notices/USN-4997-2, https://www.cve.org/CVERecord?id=CVE-2021-23133

    Affected packages

    Package

    Name: linux-azure

    Purl: pkg:deb/ubuntu/linux-azure?arch=source&distro=trusty%2Fesm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -4.15.0-1118.131~14.04.1

    Affected versions

    4.15.0-1023.24~14.04.1
    4.15.0-1030.31~14.04.1
    4.15.0-1031.32~14.04.1
    4.15.0-1032.33~14.04.2
    4.15.0-1035.36~14.04.2
    4.15.0-1036.38~14.04.2
    4.15.0-1037.39~14.04.2
    4.15.0-1039.41~14.04.2
    4.15.0-1040.44~14.04.1
    4.15.0-1041.45~14.04.1
    4.15.0-1042.46~14.04.1
    4.15.0-1045.49~14.04.1
    4.15.0-1046.50~14.04.1
    4.15.0-1047.51~14.04.1
    4.15.0-1049.54~14.04.1
    4.15.0-1050.55~14.04.1
    4.15.0-1051.56~14.04.1
    4.15.0-1052.57~14.04.1
    4.15.0-1055.60~14.04.1
    4.15.0-1056.61~14.04.1
    4.15.0-1057.62~14.04.1
    4.15.0-1059.64~14.04.1
    4.15.0-1060.65~14.04.1
    4.15.0-1061.66~14.04.1
    4.15.0-1063.68~14.04.1
    4.15.0-1064.69~14.04.1
    4.15.0-1066.71~14.04.1
    4.15.0-1067.72~14.04.1
    4.15.0-1069.74~14.04.1
    4.15.0-1071.76~14.04.1
    4.15.0-1074.79~14.04.1
    4.15.0-1077.82~14.04.1
    4.15.0-1082.92~14.04.1
    4.15.0-1083.93~14.04.1
    4.15.0-1089.99~14.04.1
    4.15.0-1091.101~14.04.1
    4.15.0-1092.102~14.04.1
    4.15.0-1093.103~14.04.1
    4.15.0-1095.105~14.04.1
    4.15.0-1096.106~14.04.1
    4.15.0-1098.109~14.04.1
    4.15.0-1100.111~14.04.1
    4.15.0-1102.113~14.04.1
    4.15.0-1103.114~14.04.1
    4.15.0-1106.118~14.04.1
    4.15.0-1108.120~14.04.1
    4.15.0-1109.121~14.04.1
    4.15.0-1110.122~14.04.1
    4.15.0-1111.123~14.04.1
    4.15.0-1112.124~14.04.1
    4.15.0-1113.126~14.04.1
    4.15.0-1114.127~14.04.1
    4.15.0-1115.128~14.04.1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2021-23133 | CVE-DB