{"answers":{"affected":"It affects 3 products.","exploited":"There is no known exploitation of CVE-2021-21381 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-21381 is a high-severity path traversal vulnerability in Debian Debian Linux, published on 11 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2021-21381 and fix it if it is affected.\n\nWhat it is: CVE-2021-21381 is a high-severity path traversal vulnerability in Debian Debian Linux, published on 11 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2021-21381 in the wild and no public exploit code.\n\nAffected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2021-21381/ (Markdown: https://insights.sbomify.com/CVE-2021-21381/index.md)","id":"CVE-2021-21381","markdown":"https://insights.sbomify.com/CVE-2021-21381/index.md","name":"CVE-2021-21381","record":{"aliases":["DEBIAN-CVE-2021-21381","DSA-4868-1","GHSA-xgh4-387p-hqpp","MGASA-2021-0145","RHSA-2021:1002","RHSA-2021:1068","RHSA-2021:1073","RHSA-2021:1074","UBUNTU-CVE-2021-21381","USN-4951-1"],"analysis":{"component_type":"operating_system","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Flatpak sandbox","requires_auth":"none","summary":"A malicious Flatpak app can access unauthorized files by exploiting special tokens in .desktop files, bypassing sandbox permissions.","user_interaction":"required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"fedora","vendor":"fedoraproject"},{"product":"flatpak","vendor":"flatpak"}],"cvss":{"score":7.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-74","name":"Improper Neutralization of Special Elements in Output Used by a Downstream Component"}],"description":"Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In Flatpack since version 0.9.4 and before version 1.10.2 has a vulnerability in the \"file forwarding\" feature which can be used by an attacker to gain access to files that would not ordinarily be allowed by the app's permissions. By putting the special tokens `@@` and/or `@@u` in the Exec field of a Flatpak app's .desktop file, a malicious app publisher can trick flatpak into behaving as though the user had chosen to open a target file with their Flatpak app, which automatically makes that file available to the Flatpak app. This is fixed in version 1.10.2. A minimal solution is the first commit \"`Disallow @@ and @@U usage in desktop files`\". The follow-up commits \"`dir: Reserve the whole @@ prefix`\" and \"`dir: Refuse to export .desktop files with suspicious uses of @@ tokens`\" are recommended, but not strictly required. As a workaround, avoid installing Flatpak apps from untrusted sources, or check the contents of the exported `.desktop` files in `exports/share/applications/*.desktop` (typically `~/.local/share/flatpak/exports/share/applications/*.desktop` and `/var/lib/flatpak/exports/share/applications/*.desktop`) to make sure that literal filenames do not follow `@@` or `@@u`.","ecosystems":["Red Hat:enterprise_linux:7::client","Red Hat:enterprise_linux:7::computenode","Red Hat:enterprise_linux:7::server","Red Hat:enterprise_linux:7::workstation","Red Hat:enterprise_linux:8::appstream","Red Hat:rhel_eus:8.1::appstream","Red Hat:rhel_eus:8.2::appstream"],"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":"Sandbox escape via special tokens in .desktop file","id":"CVE-2021-21381","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"debian:debian_linux","products":["debian:debian_linux","fedoraproject:fedora"],"type":"path_traversal","year":"2021"},"n_packages":43,"n_references":10,"next":{"headline":"Unsafe loopback forwarding interface in Restund","id":"CVE-2021-21382"},"packages":[{"ecosystem":"Red Hat:enterprise_linux:7::client","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::client","fixed":["0:1.0.0-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-builder","purl":"pkg:rpm/redhat/flatpak-builder","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::client","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::client","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-devel","purl":"pkg:rpm/redhat/flatpak-devel","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::client","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::computenode","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::computenode","fixed":["0:1.0.0-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-builder","purl":"pkg:rpm/redhat/flatpak-builder","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::computenode","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::computenode","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-devel","purl":"pkg:rpm/redhat/flatpak-devel","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::computenode","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:1.0.0-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-builder","purl":"pkg:rpm/redhat/flatpak-builder","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-devel","purl":"pkg:rpm/redhat/flatpak-devel","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::workstation","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::workstation","fixed":["0:1.0.0-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-builder","purl":"pkg:rpm/redhat/flatpak-builder","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::workstation","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::workstation","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-devel","purl":"pkg:rpm/redhat/flatpak-devel","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:7::workstation","fixed":["0:1.0.9-11.el7_9"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1002"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-debugsource","purl":"pkg:rpm/redhat/flatpak-debugsource","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs-debuginfo","purl":"pkg:rpm/redhat/flatpak-libs-debuginfo","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-selinux","purl":"pkg:rpm/redhat/flatpak-selinux","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-session-helper","purl":"pkg:rpm/redhat/flatpak-session-helper","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-session-helper-debuginfo","purl":"pkg:rpm/redhat/flatpak-session-helper-debuginfo","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:enterprise_linux:8::appstream","fixed":["0:1.6.2-6.el8_3"],"introduced":["0"],"last_affected":[],"package":"flatpak-tests-debuginfo","purl":"pkg:rpm/redhat/flatpak-tests-debuginfo","source":"RHSA-2021:1068"},{"ecosystem":"Red Hat:rhel_eus:8.1::appstream","fixed":["0:1.0.9-4.el8_1"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1074"},{"ecosystem":"Red Hat:rhel_eus:8.1::appstream","fixed":["0:1.0.9-4.el8_1"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1074"},{"ecosystem":"Red Hat:rhel_eus:8.1::appstream","fixed":["0:1.0.9-4.el8_1"],"introduced":["0"],"last_affected":[],"package":"flatpak-debugsource","purl":"pkg:rpm/redhat/flatpak-debugsource","source":"RHSA-2021:1074"},{"ecosystem":"Red Hat:rhel_eus:8.1::appstream","fixed":["0:1.0.9-4.el8_1"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1074"},{"ecosystem":"Red Hat:rhel_eus:8.1::appstream","fixed":["0:1.0.9-4.el8_1"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs-debuginfo","purl":"pkg:rpm/redhat/flatpak-libs-debuginfo","source":"RHSA-2021:1074"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak","purl":"pkg:rpm/redhat/flatpak","source":"RHSA-2021:1073"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak-debuginfo","purl":"pkg:rpm/redhat/flatpak-debuginfo","source":"RHSA-2021:1073"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak-debugsource","purl":"pkg:rpm/redhat/flatpak-debugsource","source":"RHSA-2021:1073"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs","purl":"pkg:rpm/redhat/flatpak-libs","source":"RHSA-2021:1073"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak-libs-debuginfo","purl":"pkg:rpm/redhat/flatpak-libs-debuginfo","source":"RHSA-2021:1073"},{"ecosystem":"Red Hat:rhel_eus:8.2::appstream","fixed":["0:1.6.2-5.el8_2"],"introduced":["0"],"last_affected":[],"package":"flatpak-selinux","purl":"pkg:rpm/redhat/flatpak-selinux","source":"RHSA-2021:1073"}],"prev":{"headline":"Rating Script Service expose XWiki to SQL injection","id":"CVE-2021-21380"},"products":["flatpak"],"published":"2021-03-11","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":"Red Hat","prefix":"RHSA"},{"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":["flatpak"]},"summary":"A malicious Flatpak app can access unauthorized files by exploiting special tokens in .desktop files, bypassing sandbox permissions.","url":"https://insights.sbomify.com/CVE-2021-21381/"}