CVE-2019-14821 Memory corruption in Kernel

What is CVE-2019-14821?

CVE-2019-14821 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 19 Sep 2019. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.

Weakness: CWE-787

Which versions are affected by CVE-2019-14821?

It affects 28 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Aff A700s Firmware, Netapp Data Availability Services and 22 more.

How do I fix CVE-2019-14821?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2019-14821 being exploited?

There is no known exploitation of CVE-2019-14821 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2019-14821, GHSA-5xg6-r8mx-769h, RHSA-2019:4256, UBUNTU-CVE-2019-14821.