Linux kernel io_uring TOCTOU Privilege Escalation
CVE-2023-1295 Published on June 28, 2023
Privilege escalation with IO_RING_OP_CLOSE in the Linux Kernel
A time-of-check to time-of-use issue exists in io_uring subsystem's IORING_OP_CLOSE operation in the Linux kernel's versions 5.6 - 5.11 (inclusive), which allows a local user to elevate their privileges to root. Introduced in b5dba59e0cf7e2cc4d3b3b1ac5fe81ddf21959eb, patched in 9eac1904d3364254d622bf2c771c4f85cd435fc2, backported to stable in 788d0824269bef539fe31a785b1517882eafed93.
Vulnerability Analysis
CVE-2023-1295 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is a TOCTTOU Vulnerability?
The software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state. This weakness can be security-relevant when an attacker can influence the state of the resource between check and use. This can happen with shared resources such as files, memory, or even variables in multithreaded programs.
CVE-2023-1295 has been classified to as a TOCTTOU vulnerability or weakness.
Products Associated with CVE-2023-1295
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Affected Versions
Linux Kernel:- Version 5.6, <= 5.11 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.