CVE-2021-3492

Description

Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562.

Related CPE's

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References

https://www.openwall.com/lists/oss-security/2021/04/16/2

Mailing ListThird Party Advisory

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333

Mailing ListPatchVendor Advisory

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6

Mailing ListPatchVendor Advisory

https://ubuntu.com/security/notices/USN-4917-1

Vendor Advisory

https://www.zerodayinitiative.com/advisories/ZDI-21-422/

Third Party AdvisoryVDB Entry

CvssV3 impact

BaseSeverity	HIGH
ConfidentialityImpact	HIGH
AttackComplexity	LOW
Scope	UNCHANGED
AttackVector	LOCAL
AvailabilityImpact	HIGH
IntegrityImpact	HIGH
PrivilegesRequired	LOW
BaseScore	7.8
VectorString	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Version	3.1
UserInteraction	NONE

CvssV2 impact

AccessComplexity	LOW
ConfidentialityImpact	COMPLETE
AvailabilityImpact	COMPLETE
IntegrityImpact	COMPLETE
BaseScore	7.2
VectorString	AV:L/AC:L/Au:N/C:C/I:C/A:C
Version	2.0
AccessVector	LOCAL
Authentication	NONE