CVE-2023-0240

Use after free in io_uring in the Linux Kernel

Description

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.

Category

7.8
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.02%
Vendor Advisory kernel.org
Affected: Linux Linux Kernel
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-0240?
CVE-2023-0240 has been scored as a high severity vulnerability.
How to fix CVE-2023-0240?
To fix CVE-2023-0240, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-0240 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-0240 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-0240?
CVE-2023-0240 affects Linux Linux Kernel.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.