CVE-2021-47259

Severity CVSS v4.0:

Pending analysis

Type:

CWE-416 Use After Free

Publication date:

21/05/2024

Last modified:

04/04/2025

Description

In the Linux kernel, the following vulnerability has been resolved: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	4.13 (including)	4.14.237 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	4.15 (including)	4.19.195 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	4.20 (including)	5.4.126 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.5 (including)	5.10.44 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.11 (including)	5.12.11 (excluding)
cpe:2.3:o:linux:linux_kernel:5.13:rc1::::::
cpe:2.3:o:linux:linux_kernel:5.13:rc2::::::
cpe:2.3:o:linux:linux_kernel:5.13:rc3::::::
cpe:2.3:o:linux:linux_kernel:5.13:rc4::::::
cpe:2.3:o:linux:linux_kernel:5.13:rc5::::::

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-47259

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools