CVE-2021-42008

HIGHNVD 7.87.8—Elevated

7.8

The decode_data function in drivers/net/hamradio/6pack.c in the Linux kernel before 5.13.13 has a slab out-of-bounds write. Input from a process that has the CAP_NET_ADMIN capability can lead to root access.

CVSS v3: 7.8
EG Score: 7.8(medium)
EPSS: 76.5%
KEV: Not listed

Published

October 5, 2021

Last Modified

November 21, 2024

References (10)

cve@mitrehttps://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.13
cve@mitrehttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19d1532a187669ce86d5a2696eb7275310070793
cve@mitrehttps://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
cve@mitrehttps://security.netapp.com/advisory/ntap-20211104-0002/
cve@mitrehttps://www.youtube.com/watch?v=d5f9xLK8Vhw
af854a3a-2127-422b-91ae-364da2661108https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.13
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19d1532a187669ce86d5a2696eb7275310070793
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20211104-0002/
af854a3a-2127-422b-91ae-364da2661108https://www.youtube.com/watch?v=d5f9xLK8Vhw

Patch Availability(7)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	linux-headers-5.11.0-1021-raspi (5.11.0-1021.22) @ hirsute	2026-05-26	ubuntu
ubuntu	linux-virtual-hwe-16.04-edge (4.15.0.161.150) @ bionic	2026-05-26	ubuntu
ubuntu	linux-tools-oem-20.04-edge (5.10.0.1050.52) @ focal	2026-05-26	ubuntu
ubuntu	linux-image-lowlatency (5.4.0.89.93) @ focal	2026-05-26	ubuntu
ubuntu	linux-headers-5.4.0-1062-azure (5.4.0-1062.65) @ focal	2026-05-26	ubuntu
ubuntu	linux-image-lowlatency (4.4.0.219.226) @ xenial	2026-05-26	ubuntu
ubuntu	linux-image-lowlatency (4.4.0.222.229) @ xenial	2026-05-26	ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-787Out-of-bounds Write

All Vendor Advisories

(8)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-29 13:42 UTCEPSS rescore

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoC0xdevil/CVE-2021-42008
First seen Dec 3, 2021
CVE-2021-42008: Exploiting A 16-Year-Old Vulnerability In The Linux 6pack Driver
Open source ↗
GitHub PoCnumanturle/CVE-2021-42008
First seen Dec 3, 2021
Exploiting A 16-Year-Old Vulnerability In The Linux 6pack Driver
Open source ↗

Frequently asked(5)

What is CVE-2021-42008?

CVE-2021-42008 is a high vulnerability published on October 5, 2021. The decodedata function in drivers/net/hamradio/6pack.c in the Linux kernel before 5.13.13 has a slab out-of-bounds write. Input from a process that has the CAPNET_ADMIN capability can lead to root access.

When was CVE-2021-42008 disclosed?

CVE-2021-42008 was first published in the National Vulnerability Database on October 5, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-42008 actively exploited?

CVE-2021-42008 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 76.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-42008?

CVE-2021-42008 has a CVSS v3 base score of 7.8 (NVD).

How do I remediate CVE-2021-42008?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42008, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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