# CVE-2020-25211: Integer overflow in n/a > Local attackers can overflow a buffer in the Linux kernel's conntrack netlink configuration, causing crashes or incorrect protocol handling. - **Severity:** Medium 6.0 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 9 Sep 2020 - **Updated:** 4 Aug 2024 - **Also known as:** DEBIAN-CVE-2020-25211, GHSA-q7g7-fmmr-xhp8, RHSA-2021:0003, RHSA-2021:0004, RHSA-2021:0189, UBUNTU-CVE-2020-25211 ## What is CVE-2020-25211? CVE-2020-25211 is a medium-severity vulnerability in Debian Debian Linux, published on 9 Sep 2020. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel through 5.8.7, local attackers able to inject conntrack netlink configuration could overflow a local buffer, causing crashes or triggering use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c, aka CID-1cc5ef91d2ff. Weakness: CWE-120 (Buffer Copy without Checking Size of Input) ## Which versions are affected by CVE-2020-25211? It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bpftool` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `bpftool-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-core` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-core` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-modules` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-modules-extra` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-aarch64` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-ppc64le` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-s390x` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-doc` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-modules` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-modules-extra` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-tools` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-tools-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-tools-libs` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump-core` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump-modules` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-zfcpdump-modules-extra` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `perf` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `perf-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `python3-perf` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `python3-perf-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-240.10.1.el8_3 | | `bpftool-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-aarch64` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-ppc64le` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | | `kernel-tools-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.18.0-240.10.1.el8_3 | Products: Debian Debian Linux, Fedoraproject Fedora, Linux kernel. ## How do I fix CVE-2020-25211? Apply the vendor's patch. ## Is CVE-2020-25211 being exploited? There is no known exploitation of CVE-2020-25211 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-25211 and fix it if it is affected. What it is: CVE-2020-25211 is a medium-severity vulnerability in Debian Debian Linux, published on 9 Sep 2020. 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-2020-25211 in the wild and no public exploit code. Affected product: Debian Debian 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-2020-25211/ (Markdown: https://insights.sbomify.com/CVE-2020-25211/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25211 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25211 - OSV: https://osv.dev/vulnerability/CVE-2020-25211 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-25211/ Summaries are generated and may contain mistakes; the official description above is the record.