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CVE-2022-4696

HIGHCVSS 7.8/10EPSS 0.41%

Last modified

CVE-2022-4696 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. There exists a use-after-free vulnerability in the Linux kernel through io_uring and the IORING_OP_SPLICE operation. If IORING_OP_SPLICE is missing the IO_WQ_WORK_FILES flag, which signals that the operation won't use current->nsproxy, so its reference counter is not increased. EPSS estimates a 0.41% chance of exploitation in the next 30 days.

Description

There exists a use-after-free vulnerability in the Linux kernel through io_uring and the IORING_OP_SPLICE operation. If IORING_OP_SPLICE is missing the IO_WQ_WORK_FILES flag, which signals that the operation won't use current->nsproxy, so its reference counter is not increased. This assumption is not always true as calling io_splice on specific files will call the get_uts function which will use current->nsproxy leading to invalidly decreasing its reference counter later causing the use-after-free vulnerability. We recommend upgrading to version 5.10.160 or above

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.41%

32.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 5.10, < 5.12

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2022-4696?
There exists a use-after-free vulnerability in the Linux kernel through io_uring and the IORING_OP_SPLICE operation. If IORING_OP_SPLICE is missing the IO_WQ_WORK_FILES flag, which signals that the operation won't use current->nsproxy, so its reference counter is not increased. This assumption is not always true as calling io_splice on specific files will call the get_uts function which will use current->nsproxy leading to invalidly decreasing its reference counter later causing the use-after-free vulnerability. We recommend upgrading to version 5.10.160 or above
How severe is CVE-2022-4696?
CVE-2022-4696 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.
How do I fix CVE-2022-4696?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-4696?

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Source: NVD / NIST