CVE-2021-3489

highpriority · track · 31EPSS 0.005 · 46 %ileEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.55% (46th) EPSS
CVSS 7.2 · high
Is it mine?
29 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).

01

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.07.2highAV:L/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 3.9 · impact 10
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.17.8highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU
v3.17.8highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · security@ubuntu.comexploitability 1.1 · impact 6
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-119USCWE-119USCWE-787US
03

affected products (29)

Products and version ranges known to be affected.

showing 20 of 29
04

advisories (1)

Vendor and ecosystem advisories describing this.

  • PUB-A-1908772792021-10-01vendor · osvUS

    In __bpf_ringbuf_reserve of ringbuf.c, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.

05

also known as (5)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvNVDCVE.orgMITRE
published 2021-06-04modified 2026-06-17
08

references (30)

External citations — patches, advisories, analysis.

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