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UBUNTU-CVE-2021-31829 Moderate

UBUNTU-CVE-2021-31829

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.

Exploit probability Not scored
Published May 6, 2021
Required by Not available
Last source change August 19, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:18.04:LTS linux-oem

50 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.0

6 explicit affected versions

Ubuntu:20.04:LTS linux-raspi2

6 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-azure-fde-5.15

57 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-fips

1 explicit affected versions

Ubuntu:Pro:14.04:LTS linux

191 explicit affected versions

Ubuntu:18.04:LTS linux-aws

67 explicit affected versions

Ubuntu:20.04:LTS linux-kvm

27 explicit affected versions

Ubuntu:18.04:LTS linux-oracle

47 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-azure-fips

20 explicit affected versions

Ubuntu:18.04:LTS linux

77 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.8

1 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-kvm

121 explicit affected versions

Ubuntu:16.04:LTS linux-hwe-edge

23 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:24.04:LTS linux-raspi-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.8

19 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.0

7 explicit affected versions

Ubuntu:20.04:LTS linux-riscv

12 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iot-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-gcp

29 explicit affected versions

Ubuntu:20.04:LTS linux

37 explicit affected versions

Ubuntu:20.04:LTS linux-azure

29 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-aws

120 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-4.15

22 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

14 explicit affected versions

Ubuntu:18.04:LTS linux-snapdragon

44 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.10

12 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws

144 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.6

29 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:18.04:LTS linux-kvm

61 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-aws

32 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

33 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.3

10 explicit affected versions

Ubuntu:Pro:16.04:LTS linux

188 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws-hwe

46 explicit affected versions

Ubuntu:Nvidia-BlueField:24.04:LTS linux-bluefield

11 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-gcp

69 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.8

1 explicit affected versions

Ubuntu:20.04:LTS linux-oracle

29 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

2 explicit affected versions

Ubuntu:18.04:LTS linux-raspi2

64 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-lts-xenial

165 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-5.4

25 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-gke

9 explicit affected versions

Ubuntu:18.04:LTS linux-azure-4.15

23 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-fips

26 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.8

1 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.4

19 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.4

20 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-aws-fips

23 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.8

9 explicit affected versions

Ubuntu:18.04:LTS linux-raspi-5.4

18 explicit affected versions

Ubuntu:18.04:LTS linux-azure

44 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.3

16 explicit affected versions

Ubuntu:18.04:LTS linux-gkeop-5.4

14 explicit affected versions

Ubuntu:18.04:LTS linux-gcp

38 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.3

9 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.4

19 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

97 explicit affected versions

Ubuntu:20.04:LTS linux-bluefield

3 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-azure

77 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-azure

54 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.8

1 explicit affected versions

Ubuntu:18.04:LTS linux-dell300x

13 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-oracle

45 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.4

19 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

43 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-hwe

92 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-edge

12 explicit affected versions

Ubuntu:20.04:LTS linux-raspi

22 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop

9 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-gcp-fips

1 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

related USN-4997-1
related USN-4997-2

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2021-31829

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.

View original source

05 / REFERENCES

Further evidence