CVE-2021-3490
CVSS v3
7.8
HIGH
EPSS Score
3.7 %
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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).
Technical details
- Published
- 2021-06-04
Frequently asked questions
What is CVE-2021-3490?
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).
Is CVE-2021-3490 actively exploited?
Active exploitation of CVE-2021-3490 has not been confirmed. The EPSS score is 3.7%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-3490?
CVE-2021-3490 has a CVSS v3 base score of 7.8 (HIGH severity).
Is CVE-2021-3490 affecting your environment?
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