Resource exhaustion in Linux kernel - CVE-2021-20265

Vulnerability identifier: #VU51548

CSH Severity: Low

CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

CVE-ID: CVE-2021-20265

CWE-ID: CWE-400

Exploitation vector: Local access

Exploit availability: No public exploit available

Affected software:
Linux kernel
Red Hat Enterprise Linux Server - Extended Life Cycle Support
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems)
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux for Real Time for NFV
HPE Helion Openstack
SUSE OpenStack Cloud
SUSE OpenStack Cloud Crowbar
SUSE Linux Enterprise Server
SUSE Linux Enterprise Debuginfo
SUSE Linux Enterprise Server for SAP
SUSE Linux Enterprise High Availability
kernel (Red Hat package)
kernel-rt (Red Hat package)
kgraft-patch-4_4_180-94_150-default-debuginfo
kgraft-patch-4_4_180-94_150-default
kernel-default-devel-debuginfo
kernel-default-man
kernel-pae
kernel-pae-base
kernel-pae-devel
kernel-default-extra
kernel-xen-extra
kernel-trace-extra
kernel-ppc64-extra
kernel-pae-extra
kernel-default-debuginfo
kernel-default-debugsource
kernel-trace-debuginfo
kernel-trace-debugsource
kernel-ppc64-base
kernel-trace-devel-debuginfo
kernel-ec2-debuginfo
kernel-ec2-debugsource
kernel-xen-debuginfo
kernel-xen-debugsource
kernel-xen-devel-debuginfo
kernel-bigmem-debuginfo
kernel-bigmem-debugsource
kernel-ppc64-debuginfo
kernel-ppc64-debugsource
kernel-ec2
kernel-pae-devel-debuginfo
kernel-pae-debugsource
kernel-pae-debuginfo
kernel-default
kernel-default-base
kernel-default-devel
kernel-source
kernel-syms
kernel-trace
kernel-trace-base
kernel-trace-devel
kernel-ec2-base
kernel-ec2-devel
kernel-xen
kernel-xen-base
kernel-xen-devel
kernel-bigmem
kernel-bigmem-base
kernel-bigmem-devel
kernel-ppc64
kernel-ppc64-devel
kernel-default-base-debuginfo
kernel-macros
kernel-devel
cluster-md-kmp-default
cluster-md-kmp-default-debuginfo
dlm-kmp-default
dlm-kmp-default-debuginfo
gfs2-kmp-default
gfs2-kmp-default-debuginfo
ocfs2-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-kgraft
Data Computing Appliance (DCA)
Session Smart Router
IBM Netezza Host Management
Juniper Junos Space

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. A local user can trigger resource exhaustion and perform a denial of service (DoS) attack.

Install updates from vendor's website.

• https://bugzilla.redhat.com/show_bug.cgi?id=1908827
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa0dc04df259ba2df3ce1920e9690c7842f8fa4b