# CVE-2019-14821: Memory corruption in Kernel > An out-of-bounds write in the Linux kernel's KVM hypervisor allows local attackers to crash the system or escalate privileges. - **Severity:** High 7.5 (`CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 19 Sep 2019 - **Updated:** 5 Aug 2024 - **Also known as:** DEBIAN-CVE-2019-14821, GHSA-5xg6-r8mx-769h, RHSA-2019:4256, UBUNTU-CVE-2019-14821 ## 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 (Out-of-bounds Write) ## Which versions are affected by CVE-2019-14821? It affects 28 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kernel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-doc` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-firmware` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-headers` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `perf` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `perf-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `python-perf` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.25.1.el6 | | `kernel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-doc` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-firmware` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-headers` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `perf` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `perf-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `python-perf` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.25.1.el6 | | `kernel` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-bootwrapper` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.25.1.el6 | Products: Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Aff A700s Firmware, Netapp Data Availability Services, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H610s Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Netapp Hci Management Node, Netapp Solidfire, Opensuse Leap, Oracle Sd-Wan Edge, Redhat Enterprise Linux and 8 more. ## How do I fix CVE-2019-14821? Apply the vendor's patch. ## 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](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild) - [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild) - [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2019-14821 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2019-14821 in the wild and no public exploit code. Affected product: Canonical Ubuntu Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2019-14821/ (Markdown: https://insights.sbomify.com/CVE-2019-14821/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2019-14821 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-14821 - OSV: https://osv.dev/vulnerability/CVE-2019-14821 --- From sbomify Insights: https://insights.sbomify.com/CVE-2019-14821/ Summaries are generated and may contain mistakes; the official description above is the record.