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UBUNTU-CVE-2020-12656 Moderate

UBUNTU-CVE-2020-12656

gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c in the rpcsec_gss_krb5 implementation in the Linux kernel through 5.6.10 lacks certain domain_release calls, leading to a memory leak. Note: This was disputed with the assertion that the issue does not grant any access not already available. It is a problem that on unloading a specific kernel module some memory is leaked, but loading kernel modules is a privileged operation. A user could also write a kernel module to consume any amount of memory they like and load that replicating the effect of this bug

Exploit probability Not scored
Published May 5, 2020
Required by Not available
Last source change August 18, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:16.04:LTS linux-snapdragon

81 explicit affected versions

Ubuntu:18.04:LTS linux-oem

42 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.0

6 explicit affected versions

Ubuntu:18.04:LTS linux-oem-osp1

23 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:14.04:LTS linux

191 explicit affected versions

Ubuntu:18.04:LTS linux-aws

47 explicit affected versions

Ubuntu:20.04:LTS linux-kvm

12 explicit affected versions

Ubuntu:18.04:LTS linux-oracle

28 explicit affected versions

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

2 explicit affected versions

Ubuntu:18.04:LTS linux

54 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: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

5 explicit affected versions

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

1 explicit affected versions

Ubuntu:20.04:LTS linux-gcp

12 explicit affected versions

Ubuntu:20.04:LTS linux

16 explicit affected versions

Ubuntu:16.04:LTS linux-kvm

49 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.0

18 explicit affected versions

Ubuntu:20.04:LTS linux-azure

12 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-4.15

4 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:16.04:LTS linux-oracle

27 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-aws

48 explicit affected versions

Ubuntu:18.04:LTS linux-snapdragon

26 explicit affected versions

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

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.6

13 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.3

9 explicit affected versions

Ubuntu:18.04:LTS linux-kvm

44 explicit affected versions

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

1 explicit affected versions

Ubuntu:20.04:LTS linux-aws

14 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

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

11 explicit affected versions

Ubuntu:16.04:LTS linux-raspi2

83 explicit affected versions

Ubuntu:20.04:LTS linux-oracle

12 explicit affected versions

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

2 explicit affected versions

Ubuntu:18.04:LTS linux-raspi2

47 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-5.4

4 explicit affected versions

Ubuntu:16.04:LTS linux-gcp

51 explicit affected versions

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

1 explicit affected versions

Ubuntu:16.04:LTS linux

112 explicit affected versions

Ubuntu:20.04:LTS linux-gke

51 explicit affected versions

Ubuntu:18.04:LTS linux-azure-4.15

5 explicit affected versions

Ubuntu:16.04:LTS linux-azure

60 explicit affected versions

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

1 explicit affected versions

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

6 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.4

2 explicit affected versions

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

1 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.4

2 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

5 explicit affected versions

Ubuntu:16.04:LTS linux-aws

70 explicit affected versions

Ubuntu:18.04:LTS linux-raspi-5.4

2 explicit affected versions

Ubuntu:16.04:LTS linux-aws-hwe

29 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:20.04:LTS linux-azure-fde

26 explicit affected versions

Ubuntu:18.04:LTS linux-raspi2-5.3

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

90 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.4

2 explicit affected versions

Ubuntu:16.04:LTS linux-hwe

73 explicit affected versions

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

25 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-azure

37 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.4

2 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

31 explicit affected versions

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

1 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-edge

12 explicit affected versions

Ubuntu:20.04:LTS linux-raspi

6 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2020-12656

gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c in the rpcsec_gss_krb5 implementation in the Linux kernel through 5.6.10 lacks certain domain_release calls, leading to a memory leak. Note: This was disputed with the assertion that the issue does not grant any access not already available. It is a problem that on unloading a specific kernel module some memory is leaked, but loading kernel modules is a privileged operation. A user could also write a kernel module to consume any amount of memory they like and load that replicating the effect of this bug

View original source

05 / REFERENCES

Further evidence