# CVE-2021-25743: ANSI escape characters in kubectl output are not being filtered > kubectl fails to filter ANSI escape sequences, allowing attackers to manipulate terminal output and potentially hide malicious activity. - **Severity:** Low 3.0 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 7 Jan 2022 - **Updated:** 16 Sep 2024 - **Also known as:** DEBIAN-CVE-2021-25743, GHSA-f9jg-8p32-2f55, GO-2022-0983, OESA-2022-2132, OESA-2023-1020, SUSE-SU-2024:2858-1, SUSE-SU-2024:2859-1, SUSE-SU-2024:2928-1 ## What is CVE-2021-25743? CVE-2021-25743 is a low-severity vulnerability in Kubernetes Kubernetes, published on 7 Jan 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link. ### Official description kubectl does not neutralize escape, meta or control sequences contained in the raw data it outputs to a terminal. This includes but is not limited to the unstructured string fields in objects such as Events. Weakness: CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences) ## Which versions are affected by CVE-2021-25743? 3 open source packages ship an affected version, including k8s.io/kubernetes. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `k8s.io/kubernetes` | Go | All versions | 1.26.0-alpha.3 | | `k8s.io/kubernetes` | Go | All versions | 1.26.0-alpha.3 | | `k8s.io/kubernetes` | Go | All versions | 1.26.0-alpha.3 | | `kubernetes1.23` | SUSE:Linux Enterprise Module for Containers 15 SP5 | All versions | 1.23.17-150500.3.15.1 | | `kubernetes1.24` | SUSE:Linux Enterprise Module for Containers 15 SP5 | All versions | 1.24.17-150500.3.19.1 | | `kubernetes1.25` | SUSE:Linux Enterprise Module for Containers 15 SP5 | All versions | 1.25.16-150400.9.10.1 | | `kubernetes1.25` | SUSE:Linux Enterprise Module for Containers 15 SP6 | All versions | 1.25.16-150400.9.10.1 | | `kubernetes1.23` | openSUSE:Leap 15.5 | All versions | 1.23.17-150500.3.15.1 | | `kubernetes1.24` | openSUSE:Leap 15.5 | All versions | 1.24.17-150500.3.19.1 | | `kubernetes1.25` | openSUSE:Leap 15.5 | All versions | 1.25.16-150400.9.10.1 | | `kubernetes1.23` | openSUSE:Leap 15.6 | All versions | 1.23.17-150500.3.15.1 | | `kubernetes1.24` | openSUSE:Leap 15.6 | All versions | 1.24.17-150500.3.19.1 | | `kubernetes1.25` | openSUSE:Leap 15.6 | All versions | 1.25.16-150400.9.10.1 | Products: Kubernetes Kubernetes. ## How do I fix CVE-2021-25743? Upgrade k8s.io/kubernetes to 1.26.0-alpha.3 or later. ## Is CVE-2021-25743 being exploited? There is no known exploitation of CVE-2021-25743 in the wild and no public exploit code. ## Other vulnerabilities in Kubernetes Kubernetes - [CVE-2018-1002105](https://insights.sbomify.com/CVE-2018-1002105/): Privilege Escalation in Kubernetes (critical 9.8) - [CVE-2017-1000056](https://insights.sbomify.com/CVE-2017-1000056/): Kubernetes Privilege Escalation (critical 9.8) - [CVE-2016-1906](https://insights.sbomify.com/CVE-2016-1906/): Authorization bypass in Openshift (critical 9.8) - [CVE-2023-3676](https://insights.sbomify.com/CVE-2023-3676/): Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation (high 8.8) - [CVE-2023-3955](https://insights.sbomify.com/CVE-2023-3955/): Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-25743 and fix it if it is affected. What it is: CVE-2021-25743 is a low-severity vulnerability in Kubernetes Kubernetes, published on 7 Jan 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2021-25743 in the wild and no public exploit code. Affected packages and fixed versions: - k8s.io/kubernetes (Go): affected all versions; fixed in 1.26.0-alpha.3 - k8s.io/kubernetes (Go): affected all versions; fixed in 1.26.0-alpha.3 - k8s.io/kubernetes (Go): affected all versions; fixed in 1.26.0-alpha.3 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-2021-25743/ (Markdown: https://insights.sbomify.com/CVE-2021-25743/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25743 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25743 - OSV: https://osv.dev/vulnerability/CVE-2021-25743 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-25743/ Summaries are generated and may contain mistakes; the official description above is the record.