PT-2021-4236 · Linux+5 · Linux Kernel+5

Manfp + 1 · Published 2021-05-11 · Updated 2025-09-29 · CVE-2021-3490

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.13-rc4 Linux kernel versions 5.7-rc1 through 5.12.3 Linux kernel versions 5.10-rc1 through 5.10.36 Linux kernel versions 5.11 through 5.11.20

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 is related to a buffer overflow in memory, allowing an attacker to execute arbitrary code in the context of the kernel.

Recommendations For Linux kernel versions prior to 5.13-rc4, update to version 5.13-rc4 or later. For Linux kernel versions 5.7-rc1 through 5.12.3, update to version 5.12.4 or later. For Linux kernel versions 5.10-rc1 through 5.10.36, update to version 5.10.37 or later. For Linux kernel versions 5.11 through 5.11.20, update to version 5.11.21 or later. As a temporary workaround, consider disabling the eBPF functionality until a patch is available.

Exploit

Fix

RCE

Out of bounds Read

Memory Corruption

Weakness Enumeration

CWE-20

CWE-125

CWE-787

Related Identifiers

ALSA-2025_16880

ALT-PU-2021-1805

ALT-PU-2021-1833

ALT-PU-2021-1855

ALT-PU-2021-1888

ALT-PU-2021-1896

ALT-PU-2021-1912

ALT-PU-2021-1920

ALT-PU-2021-1961

ALT-PU-2021-1985

ALT-PU-2021-1990

ALT-PU-2021-2293

ALT-PU-2021-2305

ALT-PU-2021-2307

ALT-PU-2021-3481

BDU:2021-04842

CVE-2021-3490

OPENSUSE-SU-2021:1975-1

OPENSUSE-SU-2021:1977-1

OPENSUSE-SU-2021_1975-1

OPENSUSE-SU-2021_1977-1

OPENSUSE-SU-2024:10728-1

OPENSUSE-SU-2024:13704-1

SUSE-SU-2021:1975-1

SUSE-SU-2021:1977-1

SUSE-SU-2021:2198-1

SUSE-SU-2021_2198-1

USN-4948-1

USN-4949-1

USN-4950-1

ZDI-21-606

Affected Products

Alt Linux

Linuxmint

Linux Kernel

Red Os

Suse

Ubuntu

References · 623

• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/cve_2021_3490_ebpf_alu32_bounds_check_lpe.rb · Exploit
• 🔥 https://github.com/chompie1337/Linux_LPE_eBPF_CVE-2021-3490 · Exploit
• 🔥 http://packetstormsecurity.com/files/164015/Linux-eBPF-ALU32-32-bit-Invalid-Bounds-Tracking-Local-Privilege-Escalation.html · Exploit
• https://ubuntu.com/security/CVE-2021-29264 · Vendor Advisory
• https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=049c4e13714ecbca567b4d5f6d563f05d431c80e · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2021:1975-1 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2021:1975-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-28971 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2024:10728-1 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-3490 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4949-1 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4950-1 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2021:1977-1 · Vendor Advisory
• https://openwall.com/lists/oss-security/2021/05/11/11 · Patch
• https://osv.dev/vulnerability/CVE-2021-3490 · Vendor Advisory