{"answers":{"affected":"4 open source packages ship an affected version, including github.com/moby/moby. It affects 3 products.","exploited":"There is no known exploitation of CVE-2021-21284 in the wild and no public exploit code.","fix":"Upgrade github.com/moby/moby to a fixed version for your release line: 19.3.15 or 20.10.3.","what":"CVE-2021-21284 is a medium-severity vulnerability in Debian Debian Linux, published on 2 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-21284 and fix it if it is affected.\n\nWhat it is: CVE-2021-21284 is a medium-severity vulnerability in Debian Debian Linux, published on 2 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-21284 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/moby/moby (Go): affected all versions; fixed in 19.3.15\n- github.com/moby/moby (Go): affected all versions; fixed in 19.3.15\n- github.com/moby/moby (Go): affected from 20.10.0-beta1; fixed in 20.10.3\n- github.com/moby/moby (Go): affected from 20.10.0-beta1; fixed in 20.10.3\n\nTask:\n1. 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.\n2. 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.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-21284/ (Markdown: https://insights.sbomify.com/CVE-2021-21284/index.md)","id":"CVE-2021-21284","markdown":"https://insights.sbomify.com/CVE-2021-21284/index.md","name":"CVE-2021-21284","record":{"aliases":["CLEANSTART-2026-QN82133","DEBIAN-CVE-2021-21284","GHSA-7452-xqpj-6rpc","UBUNTU-CVE-2021-21284"],"analysis":{"component_type":"container_or_infrastructure","fix_type":"patch","impacts":["privilege_escalation","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Docker container engine","requires_auth":"low_privilege","summary":"Attackers with remapped root access can escalate to real root by modifying Docker files when userns-remap is enabled.","user_interaction":"not_required","vuln_class":"privilege_escalation"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"docker","vendor":"docker"},{"product":"e-series_santricity_os_controller","vendor":"netapp"}],"cvss":{"score":6.8,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-22","name":"Improper Limitation of a Pathname to a Restricted Directory"}],"description":"In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using \"--userns-remap\", if the root user in the remapped namespace has access to the host filesystem they can modify files under \"/var/lib/docker/\u003cremapping\u003e\" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"privilege escalation in Moby","id":"CVE-2021-21284","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"debian:debian_linux","products":["debian:debian_linux","netapp:e-series_santricity_os_controller"],"type":"privilege_escalation","year":"2021"},"n_packages":4,"n_references":8,"next":{"headline":"Docker daemon crash during image pull of malicious image","id":"CVE-2021-21285"},"packages":[{"ecosystem":"Go","fixed":["19.3.15"],"introduced":["0"],"last_affected":[],"package":"github.com/moby/moby","purl":null,"source":"GHSA-7452-xqpj-6rpc"},{"ecosystem":"Go","fixed":["19.3.15"],"introduced":["0"],"last_affected":[],"package":"github.com/moby/moby","purl":"pkg:golang/github.com/moby/moby","source":"GHSA-7452-xqpj-6rpc"},{"ecosystem":"Go","fixed":["20.10.3"],"introduced":["20.10.0-beta1"],"last_affected":[],"package":"github.com/moby/moby","purl":null,"source":"GHSA-7452-xqpj-6rpc"},{"ecosystem":"Go","fixed":["20.10.3"],"introduced":["20.10.0-beta1"],"last_affected":[],"package":"github.com/moby/moby","purl":"pkg:golang/github.com/moby/moby","source":"GHSA-7452-xqpj-6rpc"}],"prev":{"headline":"XSS in Flarum Sticky extension.","id":"CVE-2021-21283"},"products":["moby"],"published":"2021-02-02","related":[{"cvss_score":10,"headline":"ProFTPD Improper Access Control","id":"CVE-2015-3306","kev_date_added":"2026-10-08","published":"2015-05-18"},{"cvss_score":9.9,"headline":"RoundCube Webmail Deserialization of Untrusted Data","id":"CVE-2025-49113","kev_date_added":"2026-02-20","published":"2025-06-02"},{"cvss_score":9.8,"headline":"GNU InetUtils Argument Injection","id":"CVE-2026-24061","kev_date_added":"2026-01-26","published":"2026-01-21"},{"cvss_score":9.8,"headline":"Linux Kernel Improper Check for Unusual or Exceptional Conditions","id":"CVE-2025-39682","kev_date_added":"2026-09-18","published":"2025-09-05"},{"cvss_score":9.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2024-9680","kev_date_added":"2024-10-15","published":"2024-10-09"},{"cvss_score":9.8,"headline":"RARLAB UnRAR Directory Traversal","id":"CVE-2022-30333","kev_date_added":"2022-08-09","published":"2022-05-09"},{"cvss_score":9.8,"headline":"Roundcube Webmail SQL Injection","id":"CVE-2021-44026","kev_date_added":"2023-06-22","published":"2021-11-19"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-03","vendors":["moby"]},"summary":"Attackers with remapped root access can escalate to real root by modifying Docker files when userns-remap is enabled.","url":"https://insights.sbomify.com/CVE-2021-21284/"}