CVE-2021-47160

Cross-bridge traffic leakage via stale port matrix

Published Mar 25, 2024 · Updated Aug 5, 2026

Information disclosure in the Linux MT7530 DSA driver allows attackers to read traffic across logically isolated network bridges. mt7530_port_set_vlan_aware sets PCR_MATRIX to all members when VLAN filtering is enabled but does not restore isolation when filtering is disabled. Exploitation requires MT7530 switch hardware, a shared Layer 2 network, and bridges whose VLAN filtering was enabled and then disabled.

CVSS severity8.1
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in the Linux MT7530 DSA driver allows attackers to read traffic across logically isolated network bridges. mt7530_port_set_vlan_aware sets PCR_MATRIX to all members when VLAN filtering is enabled but does not restore isolation when filtering is disabled. Exploitation requires MT7530 switch hardware, a shared Layer 2 network, and bridges whose VLAN filtering was enabled and then disabled.

The record

CVE
CVE-2021-47160
Published
Mar 25, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1040
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.16
  2. Affected versionversion=83163f7dca5684816d01c8ccf4857aa74801e7b7 <474a2ddaa192777522a7499784f1d60691cd831a
  3. Affected versionversion=83163f7dca5684816d01c8ccf4857aa74801e7b7 <4fe4e1f48ba119bdbc7c897c83b04ba0d08f5488
  4. Affected versionversion=83163f7dca5684816d01c8ccf4857aa74801e7b7 <82ae35b6c14feae5f216913d5b433e143c756d4e
  5. Affected versionversion=83163f7dca5684816d01c8ccf4857aa74801e7b7 <ae389812733b1b1e8e07fcc238e41db166b5c78d
  6. Affected versionversion=83163f7dca5684816d01c8ccf4857aa74801e7b7 <b91117b66fe875723a4e79ec6263526fffdb44d2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=83163f7dca5684816d01c8ccf4857aa74801e7b7 <474a2ddaa192777522a7499784f1d60691cd831a; version=83163f7dca5684816d01c8ccf4857aa74801e7b7 <4fe4e1f48ba119bdbc7c897c83b04ba0d08f5488; version=83163f7dca5684816d01c8ccf4857aa74801e7b7 <82ae35b6c14feae5f216913d5b433e143c756d4e; version=83163f7dca5684816d01c8ccf4857aa74801e7b7 <ae389812733b1b1e8e07fcc238e41db166b5c78d; version=83163f7dca5684816d01c8ccf4857aa74801e7b7 <b91117b66fe875723a4e79ec6263526fffdb44d2

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
8.1Linux Kernel CVE TeamCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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