# CVE-2020-8622: A truncated TSIG response can lead to an assertion failure > An attacker can cause a denial of service in BIND by sending a truncated TSIG response, triggering an assertion failure and crashing the server. - **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 21 Aug 2020 - **Updated:** 16 Sep 2024 - **Also known as:** ALPINE-CVE-2020-8622, DEBIAN-CVE-2020-8622, GHSA-fh6r-7j2f-pmw4, RHSA-2020:4183, SUSE-SU-2021:2876-1, UBUNTU-CVE-2020-8622, USN-4468-2 ## What is CVE-2020-8622? CVE-2020-8622 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 21 Aug 2020. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description In BIND 9.0.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit. Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit. Weakness: CWE-617 (Reachable Assertion) ## Which versions are affected by CVE-2020-8622? It affects 8 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bind` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-chroot` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-devel` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-libs` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-sdb` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-utils` | Red Hat:enterprise_linux:6::client | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-chroot` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-libs` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-sdb` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-utils` | Red Hat:enterprise_linux:6::computenode | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-chroot` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-devel` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-libs` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-sdb` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-utils` | Red Hat:enterprise_linux:6::server | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-chroot` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-debuginfo` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-libs` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-sdb` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind-utils` | Red Hat:enterprise_linux:6::workstation | All versions | 32:9.8.2-0.68.rc1.el6_10.8 | | `bind` | SUSE:HPE Helion OpenStack 8 | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:Linux Enterprise Server 12 SP3-BCL | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:OpenStack Cloud 8 | All versions | 9.9.9P1-63.28.1 | | `bind` | SUSE:OpenStack Cloud Crowbar 8 | All versions | 9.9.9P1-63.28.1 | Products: Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Isc Bind, Netapp Steelstore Cloud Integrated Storage, Opensuse Leap, Oracle Communications Diameter Signaling Router, Synology Dns Server. ## How do I fix CVE-2020-8622? Upgrade to a fixed version. ## Is CVE-2020-8622 being exploited? There is no known exploitation of CVE-2020-8622 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-2020-8622 and fix it if it is affected. What it is: CVE-2020-8622 is a medium-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 21 Aug 2020. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-8622 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-2020-8622/ (Markdown: https://insights.sbomify.com/CVE-2020-8622/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8622 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8622 - OSV: https://osv.dev/vulnerability/CVE-2020-8622 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-8622/ Summaries are generated and may contain mistakes; the official description above is the record.