SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.8EPSS 0.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.27% probability · 19th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
linux/linux kernel
Source
cve-coordination@google.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.