VulnSocial

CVE-2021-3490General(canonical / linux_kernel)

LOWCVSS 7.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).

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0.5/ 10 priority

Sources & remediation

Patch / fix
Exploit / PoC references
Vendor / third-party advisories
Weakness type (CWE)
CWE-20CWE-787CWE-125

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • linux_kernel
  • ubuntu_linux

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • General: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
canonicallinux
Products
linux_kernelubuntu_linux

4 versions affected across 2 products

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-25: 107-25
Signal classification1 categories
General
1100.0%
Full discourse1 post
  • fuzzsociety@fuzzsociety_org
    General

    PWN The Penguin - From The Browser Instructor: @jeppojeps A hands-on primer on modern Linux kernel & glibc exploitation. Every flagship CVE is paired with the primitive its lecture teaches — the exploit is the lesson. All labs escalate to root, verified end-to-end. Curriculum, CVE-2023-32233 CVE-2021-3490 CVE-2022-0847 Support, 24/7 support via Discord — we've run this with a large cohort of students (happy to connect you with a few)., Average response time: under 1 hour., Dedicated DevOps on call for any lab/infra issues., Prereqs: basic x86/x64 asm · Linux kernel basics · the parent primer course.

    Post summary

    The text advertises a training course covering several CVEs but does not provide PoCs, exploit code, patch information, or technical details.

    00014262
    1.2K followersView on X
CPE platform detail8 entries

8 of 8 entries

PartVendorProductVersionTarget SWTarget HW
OScanonicalubuntu_linux20.04--
OScanonicalubuntu_linux20.10--
OScanonicalubuntu_linux21.04--
OSlinuxlinux_kernel---
OSlinuxlinux_kernel5.13--
OSlinuxlinux_kernel5.13--
OSlinuxlinux_kernel5.13--
OSlinuxlinux_kernel5.13--

Explore more

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