Ubuntu linux kernel shiftfs file system double free vulnerability
CVE-2021-3492

8.8HIGH

Key Information:

Vendor

Ubuntu

Status
Linux Kernel
Vendor
CVE Published:
15 April 2021

What is CVE-2021-3492?

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.

Affected Version(s)

Linux kernel 5.8 kernel < 5.8.0-50.56

Linux kernel 5.4 kernel < 5.4.0-72.80

References

https://www.openwall.com/lists/oss-security/2021/04/16/2
x_refsource_MISC
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/l...
x_refsource_MISC
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/l...
x_refsource_MISC

EPSS Score

23% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Vincent Dehors of Synactiv Digital Security
.