CVE-2021-3491

The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).

CVSS v3.0 8.8 HIGH
CVSS v2.0 7.2 HIGH

8.8^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 2.0 / Impact : 6.0

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

7.2^/10

CVSS v2.0 : HIGH

Vector : AV:L/AC:L/Au:N/C:C/I:C/A:C

Exploitability : 3.9 / Impact : 10.0

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

References

Link	Resource
https://ubuntu.com/security/notices/USN-4949-1	Third Party Advisory
https://ubuntu.com/security/notices/USN-4950-1	Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d1f82808877bb10d3deee7cf3374a4eb3fb582db	Patch Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-589/	Third Party Advisory VDB Entry
https://www.openwall.com/lists/oss-security/2021/05/11/13	Mailing List Patch Third Party Advisory
https://security.netapp.com/advisory/ntap-20210716-0004/	Third Party Advisory

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Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

Configuration 2 (hide)

OR	cpe:2.3:o:canonical:ubuntu_linux:20.04::::lts:::
	cpe:2.3:o:canonical:ubuntu_linux:20.10:::::::*
	cpe:2.3:o:canonical:ubuntu_linux:21.04:::::::*

Information

Published : 2021-06-03 19:15

Updated : 2021-09-14 07:31

NVD link : CVE-2021-3491

Mitre link : CVE-2021-3491

JSON object : View

CWE

CWE-787

Out-of-bounds Write

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Products Affected

canonical

ubuntu_linux

linux

linux_kernel

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