cbcvebase.
CVE-2023-32233
published 2023-05-08

CVE-2023-32233: In the Linux kernel through 6.3.1, a use-after-free in Netfilter nf_tables when processing batch requests can be abused to perform arbitrary read and write…

PriorityP181high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
12.97%
95.9th percentile
In the Linux kernel through 6.3.1, a use-after-free in Netfilter nf_tables when processing batch requests can be abused to perform arbitrary read and write operations on kernel memory. Unprivileged local users can obtain root privileges. This occurs because anonymous sets are mishandled.

Affected

35 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.27-1 (bookworm)linux 6.1.27-1 (bookworm)
googlechrome_chrome
linuxlinux_kernel>= 0 < 5.10.179-15.10.179-1
linuxlinux_kernel>= 0 < 6.1.27-16.1.27-1
linuxlinux_kernel>= 0 < 6.1.27-16.1.27-1
linuxlinux_kernel>= 0 < 6.1.27-16.1.27-1
linuxlinux_kernel>= 0 < 4.15.0-212.2234.15.0-212.223
linuxlinux_kernel>= 0 < 5.4.0-150.1675.4.0-150.167
linuxlinux_kernel>= 0 < 5.15.0-73.805.15.0-73.80
linuxlinux_kernel>= 0 < 4.4.0-241.2754.4.0-241.275
linuxlinux_kernel>= 0 < 5.4.0-150.1675.4.0-150.167
linuxlinux_kernel>= 0 < 5.15.0-73.805.15.0-73.80
linuxlinux_kernel>= 3.13 < 4.14.3154.14.315
linuxlinux_kernel>= 4.15 < 4.19.2834.19.283
linuxlinux_kernel>= 4.20 < 5.4.2435.4.243
linuxlinux_kernel>= 5.11 < 5.15.1115.15.111
linuxlinux_kernel>= 5.16 < 6.1.286.1.28
linuxlinux_kernel>= 5.5 < 5.10.1805.10.180
linuxlinux_kernel>= 6.2 < 6.2.156.2.15
linuxlinux_kernel>= 6.3 < 6.3.26.3.2
msrccbl2_kernel_5.15.112.1-1_on_cbl_mariner_2.0
msrccbl_mariner_1.0_arm
msrccbl_mariner_1.0_x64
msrccbl_mariner_2.0_arm
msrccbl_mariner_2.0_x64

Detection & IOCsextracted from sources · hover to see the quote

  • The vulnerability is in the Linux kernel's Netfilter nf_tables subsystem; detect exploitation attempts by monitoring for unprivileged users creating or manipulating nf_tables batch requests (NFT_MSG_NEWSET/NFT_MSG_DELSET for anonymous sets) via netlink sockets, especially from processes without CAP_NET_ADMIN that have created a user namespace.
  • Monitor for unprivileged local processes spawning user namespaces (CLONE_NEWUSER) combined with net namespaces (CLONE_NEWNET) to self-grant CAP_NET_ADMIN, which is the prerequisite exploitation path for this vulnerability on Red Hat/Linux systems with CONFIG_USER_NS enabled.
  • This CVE has been publicly described as a 'Container escape vulnerability'; monitor container workloads for unexpected privilege escalation or namespace manipulation via nf_tables netlink messages.
  • CVE-2023-32233 is referenced as a msg_msg spray technique reference in exploit code for related kernel UAF vulnerabilities; monitor for high-volume msgsnd() syscalls (msg_msg spray) combined with netfilter netlink activity from the same process.
  • ·Exploitation requires CAP_NET_ADMIN capability or root; on systems with CONFIG_USER_NS enabled, unprivileged users can obtain this via user namespaces. Disabling user namespaces (user.max_user_namespaces=0) or blacklisting the nf_tables kernel module mitigates the attack surface.
  • ·In OpenShift Container Platform, the vulnerability impact is rated Low because container processes are namespaced and switching namespaces inside a running OpenShift container does not yield the necessary capabilities.

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vulncheck7.8HIGH
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu7.8HIGH
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