CVE-2021-3489

Linux kernel eBPF RINGBUF map oversized allocation

HIGH

7.8

CVSS Score

Published: June 4, 2021 at 01:40 AM UTC

Updated: June 17, 2026 at 04:05 AM UTC

2 products affected across 2 vendorsLinux KernelUbuntu Linux

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Severity

HIGH7.8

Exploit prediction

EPSS 0.5%

Description

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).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Ubuntu Linux · Canonicalrubygems

95%

20.04 20.10 21.04

Linux Kernel · Linux

95%

5.11 ≤ v < 5.11.215.12 ≤ v < 5.12.45.8 ≤ v < 5.10.37linux-5.10.y ≤ v < v5.10.37linux-5.11.y ≤ v < v5.11.21linux-5.12.y ≤ v < v5.12.4trunk ≤ v < v5.13-rc4v5.8 ≤ v < 5.8*5.10.y 5.11.y 5.12.y 5.13 5.13 rc1 5.13 rc2 5.13 rc3 5.8 trunk

Affected range stops below 5.10.37, so it looks safe — our inference, not a vendor statement

Affected range stops below 5.11.21, so it looks safe — our inference, not a vendor statement

Affected range stops below 5.12.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 5.8*, so it looks safe — our inference, not a vendor statement

Affected range stops below v5.10.37, so it looks safe — our inference, not a vendor statement

Affected range stops below v5.11.21, so it looks safe — our inference, not a vendor statement

Affected range stops below v5.12.4, so it looks safe — our inference, not a vendor statement

Affected range stops below v5.13-rc4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (6)

x_refsource_MISCPatchVendor Advisory

Source: [email protected]

https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=4b81ccebaeee885ab1aa1438133f2991e3a2b6ea

x_refsource_CONFIRMThird Party Advisory

Source: [email protected]

https://security.netapp.com/advisory/ntap-20210716-0004/

Vendor Advisoryx_refsource_UBUNTUThird Party Advisory

Source: [email protected]

https://ubuntu.com/security/notices/USN-4949-1

Vendor Advisoryx_refsource_UBUNTUThird Party Advisory

Source: [email protected]

https://ubuntu.com/security/notices/USN-4950-1

Mailing Listx_refsource_MLISTThird Party Advisory

Source: [email protected]

https://www.openwall.com/lists/oss-security/2021/05/11/10

x_refsource_MISCThird Party AdvisoryVDB Entry

Source: [email protected]

https://www.zerodayinitiative.com/advisories/ZDI-21-590/

CVSS

7.8HIGHcanonical

Attack Vector: LOCAL
Complexity: HIGH
Privileges: LOW
User Interaction: NONE
Scope: CHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-119CWE-787

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