What is CVE-2021-47459?

CVE-2021-47459 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 5.4 onward and patched in 5.4.156, 5.10.76, 5.14.15 and others. CVE-2021-47459 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47459?

CVE-2021-47459 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2021-47459?

Yes, CVE-2021-47459 has been patched. Fixed versions include 5.4.156, 5.10.76, 5.14.15 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47459 actively exploited?

CVE-2021-47459 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2021-47459

High

In the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv It will trigger UAF for rx_kref of j1939_priv as following. cpu0 cpu1 j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... j1939_netdev_stop kref_put_lock(&priv->rx_kref, ...) kref_get(&priv->rx_kref, ...) REFCOUNT_WARN("addition on 0;...") ==================================================== refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Call Trace: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426/0xeb0 ? security_socket_bind+0x83/0xb0 The rx_kref's kref_get() and kref_put() should use j1939_netdev_lock to protect.

Package Linux Kernel

Published 2024-05-22

Last modified 2025-01-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2021-47459 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.4 and later are affected. Fixed in 5.4.156, 5.10.76, 5.14.15, 5.15 and their respective stable series.

Affected from

≥ 5.4

Fixed in

✓ 5.4.156 5.4.x ✓ 5.10.76 5.10.x ✓ 5.14.15 5.14.x ✓ 5.15

References

4 total

Kernel Git
https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f

Patch
Kernel Git
https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668

Patch
Kernel Git
https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d

Patch
Kernel Git
https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586

Patch

Details

CVE ID CVE-2021-47459

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2024-05-22

Modified 2025-01-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47459?

CVE-2021-47459 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 5.4 onward and has been patched in 5.4.156, 5.10.76, 5.14.15 and others. CVE-2021-47459 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47459?

CVE-2021-47459 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2021-47459?

Yes. CVE-2021-47459 has been patched. Fixed versions include 5.4.156, 5.10.76, 5.14.15 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47459 actively exploited?

No. CVE-2021-47459 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.