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UBUNTU-CVE-2023-4921 High

UBUNTU-CVE-2023-4921

A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.

Exploit probability Not scored
Published September 12, 2023
Required by Not available
Last source change August 17, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:20.04:LTS linux-intel-iotg-5.15

20 explicit affected versions

Ubuntu:22.04:LTS linux-ibm

30 explicit affected versions

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-aws-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.5

3 explicit affected versions

Ubuntu:20.04:LTS linux-raspi2

6 explicit affected versions

Ubuntu:22.04:LTS linux

39 explicit affected versions

Ubuntu:22.04:LTS linux-gkeop

25 explicit affected versions

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

47 explicit affected versions

Ubuntu:22.04:LTS linux-azure

36 explicit affected versions

Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15

25 explicit affected versions

Ubuntu:22.04:LTS linux-gke

32 explicit affected versions

Ubuntu:22.04:LTS linux-azure-5.19

7 explicit affected versions

Ubuntu:22.04:LTS linux-raspi

33 explicit affected versions

Ubuntu:20.04:LTS linux-kvm

73 explicit affected versions

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

55 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.14

35 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-tegra

9 explicit affected versions

Ubuntu:20.04:LTS linux-gke-5.15

18 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-oracle

85 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde

19 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-hwe-5.4

75 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.13

13 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.8

4 explicit affected versions

Ubuntu:16.04:LTS linux-hwe-edge

23 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-kvm

90 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

21 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.8

9 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.13

16 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2

6 explicit affected versions

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

30 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:20.04:LTS linux-riscv-5.15

23 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.5

14 explicit affected versions

Ubuntu:20.04:LTS linux-intel-5.13

7 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-azure-5.4

64 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.13

12 explicit affected versions

Ubuntu:20.04:LTS linux-gcp

78 explicit affected versions

Ubuntu:20.04:LTS linux

86 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.11

12 explicit affected versions

Ubuntu:20.04:LTS linux-azure

75 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-tegra-igx

4 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:Pro:16.04:LTS linux

156 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

37 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-aws

89 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.2

5 explicit affected versions

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

13 explicit affected versions

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

1 explicit affected versions

Ubuntu:20.04:LTS linux-iot

16 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.10

26 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.13

13 explicit affected versions

Ubuntu:22.04:LTS linux-xilinx-zynqmp

2 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:Pro:18.04:LTS linux-gcp-5.4

67 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency

36 explicit affected versions

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

1 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-raspi-5.4

62 explicit affected versions

Ubuntu:22.04:LTS linux-aws

35 explicit affected versions

Ubuntu:20.04:LTS linux-aws

78 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

33 explicit affected versions

Ubuntu:22.04:LTS linux-riscv

23 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.3

10 explicit affected versions

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

83 explicit affected versions

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

11 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.11

12 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-gcp

106 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.8

7 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.2

8 explicit affected versions

Ubuntu:20.04:LTS linux-oracle

77 explicit affected versions

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

2 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.15

25 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia

17 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-kvm

99 explicit affected versions

Ubuntu:22.04:LTS linux-oracle

33 explicit affected versions

Ubuntu:Pro:18.04:LTS linux

119 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-oem-5.17

26 explicit affected versions

Ubuntu:20.04:LTS linux-xilinx-zynqmp

12 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.2

8 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-aws

106 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-ibm-5.4

36 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.0

16 explicit affected versions

Ubuntu:22.04:LTS linux-kvm

36 explicit affected versions

Ubuntu:Pro:14.04:LTS linux

172 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.15

26 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-5.19

3 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-gcp-4.15

60 explicit affected versions

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

1 explicit affected versions

Ubuntu:20.04:LTS linux-ibm

43 explicit affected versions

Ubuntu:20.04:LTS linux-gke

51 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-azure-4.15

59 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.13

12 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iotg

24 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.1

18 explicit affected versions

Ubuntu:Nvidia-BlueField:22.04:LTS linux-bluefield

10 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

64 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-5.19

8 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.8

5 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-5.19

8 explicit affected versions

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

1 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.2

6 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-oracle-5.4

66 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.11

13 explicit affected versions

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

32 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-5.19

7 explicit affected versions

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

61 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.15

28 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.8

10 explicit affected versions

Ubuntu:20.04:LTS linux-nvidia-tegra-5.15

8 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.13

12 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-aws-5.4

65 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:22.04:LTS linux-starfive-6.2

1 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.11

13 explicit affected versions

Ubuntu:20.04:LTS linux-azure-fde

26 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop-5.15

22 explicit affected versions

Ubuntu:18.04:LTS linux-gkeop-5.4

37 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.5

14 explicit affected versions

Ubuntu:18.04:LTS linux-gcp

38 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.15

26 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.3

9 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.15

26 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-5.19

11 explicit affected versions

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

133 explicit affected versions

Ubuntu:22.04:LTS linux-gcp

33 explicit affected versions

Ubuntu:24.04:LTS linux-azure-fde

8 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.2

3 explicit affected versions

Ubuntu:20.04:LTS linux-ibm-5.15

7 explicit affected versions

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

67 explicit affected versions

Ubuntu:20.04:LTS linux-bluefield

37 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-azure

110 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-azure

89 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.8

4 explicit affected versions

Ubuntu:Pro:FIPS-preview:22.04:LTS linux-fips

1 explicit affected versions

Ubuntu:Pro:Realtime:22.04:LTS linux-realtime

31 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-oracle

82 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

43 explicit affected versions

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

32 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws

112 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-hwe

133 explicit affected versions

Ubuntu:22.04:LTS linux-aws-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-allwinner-5.19

8 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.2

9 explicit affected versions

Ubuntu:20.04:LTS linux-raspi

66 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop

55 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.5

1 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

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

36 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2023-4921

A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.

View original source

05 / REFERENCES

Further evidence