CVE-2021-23133

NameCVE-2021-23133
DescriptionA 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-2689-1, DLA-2690-1, ELA-458-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)jessie, jessie (lts)3.16.84-1vulnerable
stretch (security)4.9.320-2fixed
stretch (lts), stretch4.9.320-3fixed
buster4.19.249-2fixed
buster (security)4.19.304-1fixed
bullseye5.10.209-2fixed
bullseye (security)5.10.205-2fixed
bookworm6.1.76-1fixed
bookworm (security)6.1.85-1fixed
trixie6.6.15-2fixed
sid6.7.12-1fixed
linux-4.19 (PTS)stretch (security)4.19.232-1~deb9u1fixed
stretch (lts), stretch4.19.304-1~deb9u1fixed
linux-4.9 (PTS)jessie, jessie (lts)4.9.303-1~deb8u3fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcejessie(unfixed)end-of-life
linuxsourcestretch4.9.272-1DLA-2689-1
linuxsourcebuster4.19.194-1
linuxsource(unstable)5.10.38-1
linux-4.19sourcestretch4.19.194-1~deb9u1DLA-2690-1
linux-4.9sourcejessie4.9.272-1~deb8u2ELA-458-1

Notes

https://git.kernel.org/linus/34e5b01186858b36c4d7c87e1a025071e8e2401f
https://www.openwall.com/lists/oss-security/2021/04/18/2

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