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NVD / CVE Program· CNA Linux

CVE-2021-47101: asix: fix uninit-value in asix_mdio_read()

Noroxi assessment

Priority: Monitor (action score 28/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 8035b1a2a37a29d8c717ef84fca8fe7278bc9f03, d259f621c85949f30cc578cac813b82bb5169f56.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 8035b1a2a37a29d8c717ef84fca8fe7278bc9f03, d259f621c85949f30cc578cac813b82bb5169f56 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: asix: fix uninit-value in asix_mdio_read() asix_read_cmd() may read less than sizeof(smsr) bytes and in this case smsr will be uninitialized. Fail log: BUG: KMSAN: uninit-value in asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] BUG: KMSAN: uninit-value in asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] drivers/net/usb/asix_common.c:497 BUG: KMSAN: uninit-value in asix_mdio_read+0x3c1/0xb00 drivers/net/usb/asix_common.c:497 drivers/net/usb/asix_common.c:497 asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] drivers/net/usb/asix_common.c:497 asix_mdio_read+0x3c1/0xb00 drivers/net/usb/asix_common.c:497 drivers/net/usb/asix_common.c:497

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
Mar 4, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 12th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-47101

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.9 and later · before 5.15.12
  • linux linux kernel5.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.9affected
    • d9fe64e511144c1ee7d7555b4111f09dde9692ef and later · before d259f621c85949f30cc578cac813b82bb5169f56affected · git
    • d9fe64e511144c1ee7d7555b4111f09dde9692ef and later · before 8035b1a2a37a29d8c717ef84fca8fe7278bc9f03affected · git
    • before 4.9not affected · semver
    • 5.15.12 and later · up to and including 5.15.*not affected · semver
    • 5.16 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.22.1.el8_104.18.0-553.22.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debug-kvmbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.22.1.rt7.363.el8_104.18.0-553.22.1.rt7.363.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47099Mar 4, 2024 · veth: ensure skb entering GRO are not cloned.
    31Monitor
  • ← EarlierCVE-2021-47100Mar 4, 2024 · ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module
    22Monitor
  • Later →CVE-2021-47102Mar 4, 2024 · net: marvell: prestera: fix incorrect structure access
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux8035b1a2a37a29d8c717ef84fca8fe7278bc9f03Vendor (CNA)
Linux Linuxd259f621c85949f30cc578cac813b82bb5169f56Vendor (CNA)
almalinux:bpftool4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.22.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux5.15.15-1 · Debian:12Package registry (OSV)
opensuse:kernel-azure5.14.21-150500.33.48.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-default5.14.21-150400.24.116.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:kernel-default-base5.14.21-150400.24.116.1.150400.24.54.5 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:kernel-rt5.14.21-150400.15.76.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:kernel-source-azure5.14.21-150500.33.48.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms-azure5.14.21-150500.33.48.1 · openSUSE:Leap 15.5Package registry (OSV)
red hat:bpftool0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-debuginfo0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-devel0:4.18.0-553.22.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+17

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2024-50302260 days apartHID: core: zero-initialize the report bufferKEV
    52Plan
  • CVE-2024-47685231 days apartnetfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put()
    36Monitor
  • CVE-2024-2702258 days apartfork: defer linking file vma until vma is fully initialized
    31Monitor
  • CVE-2021-4755381 days apartsched/scs: Reset task stack state in bringup_cpu()
    31Monitor
  • CVE-2024-3689887 days apartgpiolib: cdev: fix uninitialised kfifo
    31Monitor
  • CVE-2024-50143248 days apartudf: fix uninit-value use in udf_get_fileshortad
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-908 · Use of Uninitialized Resource

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records