# CVE-2021-3672: Other in c-ares > Missing input validation in c-ares allows DNS response manipulation, potentially leading to domain hijacking and data integrity issues. - **Severity:** Medium 5.6 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Nov 2021 - **Updated:** 15 Oct 2024 - **Also known as:** ALPINE-CVE-2021-3672, ALSA-2022:2043, AZL-38359, BIT-node-2021-3672, BIT-node-min-2021-3672, BIT-pgbouncer-2021-3672, CLEANSTART-2025-VY76861, CLEANSTART-2026-EL60361, CLEANSTART-2026-QE42302, DEBIAN-CVE-2021-3672, DLA-2738-1, DSA-4954-1, ECHO-9662-31b3-1570, GHSA-hghm-3vc3-hppj, MGASA-2021-0453, OESA-2021-1313, RHSA-2022:2043, RLSA-2022:2043, SUSE-SU-2021:14776-1, SUSE-SU-2021:2690-1, SUSE-SU-2021:2760-1, UBUNTU-CVE-2021-3672, USN-5034-1, USN-5034-2, openSUSE-SU-2021:1168-1, openSUSE-SU-2021:2760-1 ## What is CVE-2021-3672? CVE-2021-3672 is a medium-severity vulnerability in Fedoraproject Fedora, published on 23 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability. Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation) ## Which versions are affected by CVE-2021-3672? 3 open source packages ship an affected version, including node, node-min and pgbouncer. It affects 17 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `node` | Bitnami | From 12.0.0 | 12.12.1, 12.22.5, 14.14.1, 14.17.5, 16.6.2 | | `node-min` | Bitnami | From 12.0.0 | 12.12.1, 12.22.5, 14.14.1, 14.17.5, 16.6.2 | | `pgbouncer` | Bitnami | All versions | 1.17.1 | | `c-ares` | AlmaLinux:8 | All versions | 1.13.0-6.el8 | | `c-ares-devel` | AlmaLinux:8 | All versions | 1.13.0-6.el8 | | `c-ares` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.13.0-6.el8 | | `c-ares-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.13.0-6.el8 | | `c-ares-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.13.0-6.el8 | | `c-ares-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.13.0-6.el8 | | `c-ares` | Rocky Linux:8 | All versions | 0:1.13.0-6.el8 | | `c-ares` | SUSE:Enterprise Storage 6 | All versions | 1.17.1+20200724-3.14.1 | | `libcares2` | SUSE:HPE Helion OpenStack 8 | All versions | 1.9.1-9.7.1 | | `c-ares` | SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise High Performance Computing 15-ESPOS | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise High Performance Computing 15-LTSS | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise Module for Basesystem 15 SP3 | All versions | 1.17.1+20200724-3.14.1 | | `libcares2` | SUSE:Linux Enterprise Point of Sale 11 SP3 | All versions | 1.7.4-7.10.3.1 | | `libcares2` | SUSE:Linux Enterprise Server 11 SP4-LTSS | All versions | 1.7.4-7.10.3.1 | | `libcares2` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server 12 SP3-BCL | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server 12 SP4-LTSS | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.9.1-9.7.1 | | `c-ares` | SUSE:Linux Enterprise Server 15 SP1-BCL | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise Server 15 SP1-LTSS | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise Server 15-LTSS | All versions | 1.17.1+20200724-3.14.1 | | `libcares2` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.9.1-9.7.1 | | `c-ares` | SUSE:Linux Enterprise Server for SAP Applications 15 | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Linux Enterprise Server for SAP Applications 15 SP1 | All versions | 1.17.1+20200724-3.14.1 | | `libcares2` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:Linux Enterprise Workstation Extension 12 SP5 | All versions | 1.9.1-9.7.1 | | `c-ares` | SUSE:Manager Proxy 4.0 | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Manager Retail Branch Server 4.0 | All versions | 1.17.1+20200724-3.14.1 | | `c-ares` | SUSE:Manager Server 4.0 | All versions | 1.17.1+20200724-3.14.1 | | `libcares2` | SUSE:OpenStack Cloud 8 | All versions | 1.9.1-9.7.1 | | `libcares2` | SUSE:OpenStack Cloud 9 | All versions | 1.9.1-9.7.1 | Products: C-Ares Project C-Ares, Fedoraproject Fedora, Nodejs Node.js, Pgbouncer Pgbouncer, Redhat Enterprise Linux, Redhat Enterprise Linux Computer Node, Redhat Enterprise Linux Eus, Redhat Enterprise Linux for Ibm Z Systems, Redhat Enterprise Linux for Ibm Z Systems Eus, Redhat Enterprise Linux for Power Little Endian, Redhat Enterprise Linux for Power Little Endian Eus, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Server Update Services for Sap Solutions, Redhat Enterprise Linux Tus, Redhat Enterprise Linux Workstation, Siemens Sinec Infrastructure Network Services. ## How do I fix CVE-2021-3672? Upgrade node to a fixed version for your release line: 12.12.1, 12.22.5, 14.14.1 or 14.17.5. ## Is CVE-2021-3672 being exploited? There is no known exploitation of CVE-2021-3672 in the wild and no public exploit code. ## Other vulnerabilities in Fedoraproject Fedora - [CVE-2022-4904](https://insights.sbomify.com/CVE-2022-4904/): Memory corruption in c-ares (high 8.6) - [CVE-2023-32067](https://insights.sbomify.com/CVE-2023-32067/): 0-byte UDP payload DoS in c-ares (high 7.5) - [CVE-2020-8277](https://insights.sbomify.com/CVE-2020-8277/): Uncontrolled Resource Consumption in node (high 7.5) - [CVE-2023-31147](https://insights.sbomify.com/CVE-2023-31147/): Insufficient randomness in generation of DNS query IDs in c-ares (medium 5.9) - [CVE-2023-31130](https://insights.sbomify.com/CVE-2023-31130/): Buffer Underwrite in ares_inet_net_pton() (medium 4.1) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-3672 and fix it if it is affected. What it is: CVE-2021-3672 is a medium-severity vulnerability in Fedoraproject Fedora, published on 23 Nov 2021. 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-2021-3672 in the wild and no public exploit code. Affected packages and fixed versions: - node (Bitnami): affected from 12.0.0; fixed in 12.12.1, 12.22.5, 14.14.1, 14.17.5, 16.6.2 - node-min (Bitnami): affected from 12.0.0; fixed in 12.12.1, 12.22.5, 14.14.1, 14.17.5, 16.6.2 - pgbouncer (Bitnami): affected all versions; fixed in 1.17.1 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-2021-3672/ (Markdown: https://insights.sbomify.com/CVE-2021-3672/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3672 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3672 - OSV: https://osv.dev/vulnerability/CVE-2021-3672 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-3672/ Summaries are generated and may contain mistakes; the official description above is the record.