01 Record

CVE-2021-47555

net: vlan: fix underflow for the real_dev refcnt

HighPUBLISHEDCNA: Linux

CNA base score7.8 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

View raw JSON

02 Description

net: vlan: fix underflow for the real_dev refcnt

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.22% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 12.7% of scored records. A rank, not a probability.

NVD base score

5.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-08-04.

Red Hat severity

Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2024-05-24 15:09Z2 YR AGO

Last updated

2026-08-05 08:48Z1 MO AGO

Reserved

2024-05-24

Assigning CNA

Linux

Record state

PUBLISHED

Severity

High (CVSS 7.8)

CNA CVSS vector

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

Weaknesses

CWE-191Integer Underflow (Wrap or Wraparound)Base
CWE-911Improper Update of Reference CountBase

Data version

5.2

Document digest

8aa1ce71bf6f5ccb02b1a9e5b1515b6f7fb395db9092584fff4bee19aa6ff049

05 Affected products

VendorProductVersionsPlatforms

LinuxLinux700602b662d7eaa816b1a3cb0abe7a85de358fd4 to < 5e44178864b38dd70b877985abd7d86fdb95f27d, e04a7a84bb77f9cdf4475340fe931389bc72331c to < 6e800ee43218a56acc93676bbb3d93b74779e555, 21032425c36ff85f16e72ca92193a8c401e4acd5 to < f7fc72a508cf115c273a7a29350069def1041890, 563bcbae3ba233c275c244bfce2efe12938f5363 to < 01d9cc2dea3fde3bad6d27f464eff463496e2b00, fca96b3f852a1b369b7b2844ce357cd689879934, 5.14.19 to < 5.15, 5.4.160 to < 5.4.163, 5.10.80 to < 5.10.83, 5.15.3 to < 5.15.6—

06 References

git.kernel.orghttps://git.kernel.org/stable/c/5e44178864b38dd70b877985abd7d86fdb95f27d
git.kernel.orghttps://git.kernel.org/stable/c/6e800ee43218a56acc93676bbb3d93b74779e555
git.kernel.orghttps://git.kernel.org/stable/c/f7fc72a508cf115c273a7a29350069def1041890
git.kernel.orghttps://git.kernel.org/stable/c/01d9cc2dea3fde3bad6d27f464eff463496e2b00

01 Record index

CVE-2021-47555

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References

02 Records

CVE-2021-47555

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References