What is CVE-2021-47125?

CVE-2021-47125 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.12 onward and patched in 5.12.10 and 5.13. CVE-2021-47125 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47125?

CVE-2021-47125 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47125?

Yes, CVE-2021-47125 has been patched. Fixed versions include 5.12.10 and 5.13. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47125 actively exploited?

CVE-2021-47125 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-47125

Medium

In the Linux kernel, the following vulnerability has been resolved: sch_htb: fix refcount leak in htb_parent_to_leaf_offload The commit ae81feb7338c ("sch_htb: fix null pointer dereference on a null new_q") fixes a NULL pointer dereference bug, but it is not correct. Because htb_graft_helper properly handles the case when new_q is NULL, and after the previous patch by skipping this call which creates an inconsistency : dev_queue->qdisc will still point to the old qdisc, but cl->parent->leaf.q will point to the new one (which will be noop_qdisc, because new_q was NULL). The code is based on an assumption that these two pointers are the same, so it can lead to refcount leaks. The correct fix is to add a NULL pointer check to protect qdisc_refcount_inc inside htb_parent_to_leaf_offload.

Package Linux Kernel

Published 2024-03-15

Last modified 2025-01-07

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.12 and later are affected. Fixed in 5.12.10, 5.13 and their respective stable series.

Affected from

≥ 5.12

Fixed in

✓ 5.12.10 5.12.x ✓ 5.13

References

2 total

Kernel Git
https://git.kernel.org/stable/c/2411c02d03892a5057499f8102d0cc1e0f852416

Patch
Kernel Git
https://git.kernel.org/stable/c/944d671d5faa0d78980a3da5c0f04960ef1ad893

Patch

Details

CVE ID CVE-2021-47125

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-03-15

Modified 2025-01-07

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47125?

CVE-2021-47125 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.12 onward and has been patched in 5.12.10 and 5.13. CVE-2021-47125 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47125?

CVE-2021-47125 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47125?

Yes. CVE-2021-47125 has been patched. Fixed versions include 5.12.10 and 5.13. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47125 actively exploited?

No. CVE-2021-47125 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.