# CVE-2020-10711: Null dereference in Kernel > A remote attacker can crash the Linux kernel via a NULL pointer dereference in the SELinux CIPSO handling, causing denial of service. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 22 May 2020 - **Updated:** 4 Aug 2024 - **Also known as:** DEBIAN-CVE-2020-10711, RHSA-2020:2103, RHSA-2020:2125, UBUNTU-CVE-2020-10711 ## What is CVE-2020-10711? CVE-2020-10711 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 22 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service. Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2020-10711? It affects 11 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kernel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-doc` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-firmware` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `perf` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `perf-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `python-perf` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:2.6.32-754.29.2.el6 | | `kernel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-doc` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-firmware` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `perf` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `perf-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `python-perf` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:2.6.32-754.29.2.el6 | | `kernel` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-bootwrapper` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debug-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-i686` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-ppc64` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | | `kernel-debuginfo-common-s390x` | Red Hat:enterprise_linux:6::server | All versions | 0:2.6.32-754.29.2.el6 | Products: Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Opensuse Leap, Redhat 3scale, Redhat Enterprise Linux, Redhat Enterprise Linux Aus, Redhat Enterprise Linux Server Tus, Redhat Messaging Realtime Grid, Redhat Openstack, Redhat Virtualization Host. ## How do I fix CVE-2020-10711? Upgrade to a fixed version. ## Is CVE-2020-10711 being exploited? There is no known exploitation of CVE-2020-10711 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-2020-10711 and fix it if it is affected. What it is: CVE-2020-10711 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 22 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-10711 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-2020-10711/ (Markdown: https://insights.sbomify.com/CVE-2020-10711/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10711 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10711 - OSV: https://osv.dev/vulnerability/CVE-2020-10711 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-10711/ Summaries are generated and may contain mistakes; the official description above is the record.