# CVE-2021-25220: DNS forwarders - cache poisoning vulnerability > Attackers can poison the DNS cache in BIND, causing clients to receive incorrect records and potentially redirecting traffic to malicious servers. - **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Mar 2022 - **Updated:** 16 Sep 2024 - **Also known as:** ALPINE-CVE-2021-25220, ALSA-2022:7790, ALSA-2022:8385, AZL-9118, CLSA-2022-1649170483, CLSA-2022-1649172068, CLSA-2022-1649172145, CLSA-2022-1649331387, CLSA-2022-1649331579, DEBIAN-CVE-2021-25220, DLA-2955-1, DSA-5105-1, GHSA-v8rf-mvwx-cx29, MGASA-2022-0108, RHSA-2022:7790, RHSA-2022:8385, RLSA-2022:7790, RLSA-2022:8385, SUSE-SU-2022:0908-1, SUSE-SU-2022:0945-1, SUSE-SU-2022:0946-1, SUSE-SU-2022:1616-1, UBUNTU-CVE-2021-25220, USN-5332-2, openSUSE-SU-2022:0945-1, openSUSE-SU-2022:0946-1 ## What is CVE-2021-25220? CVE-2021-25220 is a medium-severity vulnerability in Fedoraproject Fedora, published on 23 Mar 2022. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description BIND 9.11.0 -> 9.11.36 9.12.0 -> 9.16.26 9.17.0 -> 9.18.0 BIND Supported Preview Editions: 9.11.4-S1 -> 9.11.36-S1 9.16.8-S1 -> 9.16.26-S1 Versions of BIND 9 earlier than those shown - back to 9.1.0, including Supported Preview Editions - are also believed to be affected but have not been tested as they are EOL. The cache could become poisoned with incorrect records leading to queries being made to the wrong servers, which might also result in false information being returned to clients. Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests) ## Which versions are affected by CVE-2021-25220? It affects 12 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bind` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-devel` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-export-devel` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-export-libs` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-libs` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-libs-lite` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-license` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-lite-devel` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-devel` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-libs` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-utils` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-sdb` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-sdb-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `bind-utils` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `python3-bind` | AlmaLinux:8 | All versions | 32:9.11.36-5.el8 | | `dhcp-client` | AlmaLinux:9 | All versions | 12:4.4.2-17.b1.el9 | | `dhcp-common` | AlmaLinux:9 | All versions | 12:4.4.2-17.b1.el9 | | `dhcp-relay` | AlmaLinux:9 | All versions | 12:4.4.2-17.b1.el9 | | `dhcp-server` | AlmaLinux:9 | All versions | 12:4.4.2-17.b1.el9 | | `bind` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-chroot` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-export-libs-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-libs` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-libs-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-libs-lite` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-libs-lite-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-license` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-lite-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-libs` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-libs-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-utils` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | | `bind-pkcs11-utils-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 32:9.11.36-5.el8 | Products: Fedoraproject Fedora, Isc Bind, Juniper Junos, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Siemens Sinec Ins. ## How do I fix CVE-2021-25220? Upgrade to a fixed version. ## Is CVE-2021-25220 being exploited? There is no known exploitation of CVE-2021-25220 in the wild and no public exploit code. ## Other vulnerabilities in Fedoraproject Fedora - [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild) - [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild) - [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-25220 and fix it if it is affected. What it is: CVE-2021-25220 is a medium-severity vulnerability in Fedoraproject Fedora, published on 23 Mar 2022. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of CVE-2021-25220 in the wild and no public exploit code. Affected product: Fedoraproject Fedora. 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-2021-25220/ (Markdown: https://insights.sbomify.com/CVE-2021-25220/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25220 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25220 - OSV: https://osv.dev/vulnerability/CVE-2021-25220 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-25220/ Summaries are generated and may contain mistakes; the official description above is the record.