Vulnerability · Published Feb 17, 2023 · Assigned by Google
CVE-2023-23586Use after free in io_uring in the Linux Kernel
Medium 5.5
In plain English
A medium-severity use-after-free in Linux Kernel from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Due to a vulnerability in the io_uring subsystem, it is possible to leak kernel memory information to the user process. timens_install calls current_is_single_threaded to determine if the current process is single-threaded, but this call does not consider io_uring's io_worker threads, thus it is possible to insert a time namespace's vvar page to process's memory space via a page fault. When this time namespace is destroyed, the vvar page is also freed, but not removed from the process' memory, and a next page allocated by the kernel will be still available from the user-space process and can leak memory contents via this (read-only) use-after-free vulnerability. We recommend upgrading past version 5.10.161 or commit 788d0824269bef539fe31a785b1517882eafed93 https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | linux | 5.14.6-1 | DEBIAN-CVE-2023-23586 |
| Debian:13 | linux | 5.14.6-1 | DEBIAN-CVE-2023-23586 |
| Debian:14 | linux | 5.14.6-1 | DEBIAN-CVE-2023-23586 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2023-23586 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2023-23586 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | 5.6 – through 5.10.161 |
Weakness: CWE-416 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N