CVE-2020-12656

05.05.2020, 06:15

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

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	5.5 MEDIUM	LOCAL	LOW	LOW	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Base Score

CVSS 3.x

EPSS Score

Percentile: 29%

Affected Products (NVD)

Vendor	Product	Version
linux	linux_kernel	𝑥 ≤ 5.6.10
canonical	ubuntu_linux	14.04
canonical	ubuntu_linux	16.04
canonical	ubuntu_linux	18.04
canonical	ubuntu_linux	20.04
opensuse	leap	15.1
opensuse	leap	15.2

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

linux

bookworm	6.1.106-3 fixed
bookworm (security)	6.1.112-1 fixed
bullseye	5.10.223-1 fixed
bullseye (security)	5.10.226-1 fixed
sid	6.11.6-1 fixed
trixie	6.11.5-1 fixed

Ubuntu Releases

Ubuntu Product

Codename

linux

bionic	Fixed 4.15.0-115.116 released
eoan	ignored
focal	Fixed 5.4.0-45.49 released
groovy	not-affected
trusty	ignored
xenial	Fixed 4.4.0-186.216 released

linux-aws

bionic	Fixed 4.15.0-1080.84 released
eoan	ignored
focal	Fixed 5.4.0-1022.22 released
groovy	not-affected
trusty	ignored
xenial	Fixed 4.4.0-1111.123 released

linux-aws-5.0

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-aws-5.3

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-aws-5.4

bionic	Fixed 5.4.0-1022.22~18.04.1 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-aws-hwe

bionic	dne
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	Fixed 4.15.0-1080.84~16.04.1 released

linux-azure

bionic	ignored
eoan	ignored
focal	Fixed 5.4.0-1023.23 released
groovy	not-affected
trusty	Fixed 4.15.0-1093.103~14.04.1 released
xenial	Fixed 4.15.0-1093.103~16.04.1 released

linux-azure-4.15

bionic	Fixed 4.15.0-1093.103 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-azure-5.3

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-azure-5.4

bionic	Fixed 5.4.0-1023.23~18.04.1 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-azure-edge

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gcp

bionic	ignored
eoan	ignored
focal	Fixed 5.4.0-1022.22 released
groovy	not-affected
trusty	dne
xenial	Fixed 4.15.0-1081.92~16.04.1 released

linux-gcp-4.15

bionic	Fixed 4.15.0-1081.92 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gcp-5.3

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gcp-5.4

bionic	Fixed 5.4.0-1022.22~18.04.1 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gcp-edge

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gke-4.15

bionic	Fixed 4.15.0-1067.70 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gke-5.0

bionic	Fixed 5.0.0-1045.46 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gke-5.3

bionic	Fixed 5.3.0-1032.34~18.04.1 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gke-5.4

bionic	not-affected
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-gkeop-5.4

bionic	not-affected
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-hwe

bionic	Fixed 5.3.0-64.58~18.04.1 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	Fixed 4.15.0-115.116~16.04.1 released

linux-hwe-5.4

bionic	Fixed 5.4.0-45.49~18.04.2 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-hwe-5.8

bionic	dne
focal	not-affected
groovy	dne
trusty	dne
xenial	dne

linux-hwe-edge

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	ignored

linux-kvm

bionic	Fixed 4.15.0-1072.73 released
eoan	ignored
focal	Fixed 5.4.0-1021.21 released
groovy	not-affected
trusty	dne
xenial	Fixed 4.4.0-1077.84 released

linux-lts-trusty

bionic	dne
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-lts-xenial

bionic	dne
eoan	dne
focal	dne
groovy	dne
trusty	ignored
xenial	dne

linux-oem

bionic	Fixed 4.15.0-1094.104 released
eoan	ignored
focal	dne
groovy	dne
trusty	dne
xenial	ignored

linux-oem-5.6

bionic	dne
eoan	dne
focal	Fixed 5.6.0-1031.32 released
groovy	dne
trusty	dne
xenial	dne

linux-oem-osp1

bionic	Fixed 5.0.0-1065.70 released
eoan	ignored
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-oracle

bionic	Fixed 4.15.0-1051.55 released
eoan	ignored
focal	Fixed 5.4.0-1022.22 released
groovy	not-affected
trusty	dne
xenial	Fixed 4.15.0-1051.55~16.04.1 released

linux-oracle-5.0

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-oracle-5.3

bionic	ignored
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-oracle-5.4

bionic	Fixed 5.4.0-1022.22~18.04.1 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-raspi

bionic	dne
eoan	dne
focal	Fixed 5.4.0-1016.17 released
groovy	not-affected
trusty	dne
xenial	dne

linux-raspi-5.4

bionic	Fixed 5.4.0-1016.17~18.04.1 released
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-raspi2

bionic	Fixed 4.15.0-1068.72 released
eoan	ignored
focal	ignored
groovy	dne
trusty	dne
xenial	Fixed 4.4.0-1136.145 released

linux-raspi2-5.3

bionic	Fixed 5.3.0-1030.32~18.04.2 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	dne

linux-riscv

bionic	dne
eoan	dne
focal	Fixed 5.4.0-31.35 released
groovy	not-affected
trusty	dne
xenial	dne

linux-snapdragon

bionic	Fixed 4.15.0-1084.92 released
eoan	dne
focal	dne
groovy	dne
trusty	dne
xenial	Fixed 4.4.0-1140.148 released

Common Weakness Enumeration

CWE-401 - Missing Release of Memory after Effective Lifetime
The software does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

References

http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html

https://bugzilla.kernel.org/show_bug.cgi?id=206651

https://usn.ubuntu.com/4483-1/

https://usn.ubuntu.com/4485-1/

http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html

https://bugzilla.kernel.org/show_bug.cgi?id=206651

https://usn.ubuntu.com/4483-1/

https://usn.ubuntu.com/4485-1/