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NVD / CVE Program· CNA Linux

CVE-2021-47236: net: cdc_eem: fix tx fixup skb leak

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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 05b2b9f7d24b5663d9b47427fe1555bdafd3ea02, 14184ec5c958b589ba934da7363a2877879204df, 1bcacd6088d61c0ac6a990d87975600a81f3247e.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 05b2b9f7d24b5663d9b47427fe1555bdafd3ea02, 14184ec5c958b589ba934da7363a2877879204df, 1bcacd6088d61c0ac6a990d87975600a81f3247e 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: net: cdc_eem: fix tx fixup skb leak when usbnet transmit a skb, eem fixup it in eem_tx_fixup(), if skb_copy_expand() failed, it return NULL, usbnet_start_xmit() will have no chance to free original skb. fix it by free orginal skb in eem_tx_fixup() first, then check skb clone status, if failed, return NULL to usbnet.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 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.

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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 kernel2.6.30 and later · before 4.4.274
  • linux linux kernel4.5 and later · before 4.9.274
  • linux linux kernel4.10 and later · before 4.14.238
  • linux linux kernel4.15 and later · before 4.19.196
  • linux linux kernel4.20 and later · before 5.4.128
  • linux linux kernel5.5 and later · before 5.10.46
  • linux linux kernel5.11 and later · before 5.12.13
  • linux linux kernel5.13

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

    • 2.6.30affected
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before f12554b0ff639e74612cc01b3b4a049e098d2d65affected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before 14184ec5c958b589ba934da7363a2877879204dfaffected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before 1bcacd6088d61c0ac6a990d87975600a81f3247eaffected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before f4e6a7f19c82f39b1803e91c54718f0d7143767daffected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before 81de2ed06df8b5451e050fe6a318af3263dbff3faffected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before 05b2b9f7d24b5663d9b47427fe1555bdafd3ea02affected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before b4f7a9fc9d094c0c4a66f2ad7c37b1dbe9e78f88affected · git
    • 9f722c0978b04acba209f8ca1896ad05814bc3a3 and later · before c3b26fdf1b32f91c7a3bc743384b4a298ab53ad7affected · git
    • before 2.6.30not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.8.1.el8_104.18.0-553.8.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debug-kvmbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.8.1.rt7.349.el8_104.18.0-553.8.1.rt7.349.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-2021-47234May 21, 2024 · phy: phy-mtk-tphy: Fix some resource leaks in mtk_phy_init()
    22Monitor
  • ← EarlierCVE-2021-47235May 21, 2024 · net: ethernet: fix potential use-after-free in ec_bhf_remove
    31Monitor
  • Later →CVE-2021-47237May 21, 2024 · net: hamradio: fix memory leak in mkiss_close
    22Monitor

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 Linux05b2b9f7d24b5663d9b47427fe1555bdafd3ea02Vendor (CNA)
Linux Linux14184ec5c958b589ba934da7363a2877879204dfVendor (CNA)
Linux Linux1bcacd6088d61c0ac6a990d87975600a81f3247eVendor (CNA)
Linux Linux81de2ed06df8b5451e050fe6a318af3263dbff3fVendor (CNA)
Linux Linuxb4f7a9fc9d094c0c4a66f2ad7c37b1dbe9e78f88Vendor (CNA)
Linux Linuxc3b26fdf1b32f91c7a3bc743384b4a298ab53ad7Vendor (CNA)
Linux Linuxf12554b0ff639e74612cc01b3b4a049e098d2d65Vendor (CNA)
Linux Linuxf4e6a7f19c82f39b1803e91c54718f0d7143767dVendor (CNA)
almalinux:bpftool4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.8.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-core4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-core4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-devel4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-kvm4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules-extra4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-devel4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-kvm4.18.0-553.8.1.rt7.349.el8_10 · AlmaLinux:8Package registry (OSV)

+29

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.

No nightly-computed relations.

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
none
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
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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 (7 more)

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

All records