Use After Free in Linux Kernel
CVE-2023-0240
There is a logic error in io_uring's implementation which can be used to trigger a use-after-free vulnerability leading to privilege escalation. In the io_prep_async_work function the assumption that the last io_grab_identity call cannot return false is not true, and in this case the function will use the init_cred or the previous linked requests identity to do operations instead of using the current identity. This can lead to reference counting issues causing use-after-free. We recommend upgrading past version 5.10.161.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (18.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Linux Kernel — versions 5.10
- Linux Kernel
Weakness classification (CWE)
References
- git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/io_uring (Patch, Mailing List, Vendor Advisory)
- github.com/gregkh/linux/commit/1e6fa5216a0e59ef02e8b6b40d553238a3b81d49 (Patch, Third Party Advisory)
- kernel.dance/ (Patch, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-0240?
- CVE-2023-0240 is a high-severity vulnerability in Linux Kernel, classified under Use After Free. CVSS score: 7.8/10. Published 2023-01-30.
- How severe is CVE-2023-0240?
- High severity. CVSS v3 base score is 7.8 out of 10.