CVE-2021-3492
An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.54% probability · 73th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-401, CWE-415
- Affected
- canonical/ubuntu linux
- Source
- security@ubuntu.com
References
- http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.htmlThird Party Advisory, VDB Entry
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333Mailing List, Patch, Vendor Advisory
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6Mailing List, Patch, Vendor Advisory
- https://ubuntu.com/security/notices/USN-4917-1Vendor Advisory
- https://www.openwall.com/lists/oss-security/2021/04/16/2Mailing List, Third Party Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-422/Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.htmlThird Party Advisory, VDB Entry
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333Mailing List, Patch, Vendor Advisory
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6Mailing List, Patch, Vendor Advisory
- https://ubuntu.com/security/notices/USN-4917-1Vendor Advisory
- https://www.openwall.com/lists/oss-security/2021/04/16/2Mailing List, Third Party Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-422/Third Party Advisory, VDB Entry
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.