{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-20809 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-20809 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-20809 is a medium-severity cross-site scripting vulnerability in Six Apart Ltd. Movable Type, published on 26 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2021-20809 and fix it if it is affected.\n\nWhat it is: CVE-2021-20809 is a medium-severity cross-site scripting vulnerability in Six Apart Ltd. Movable Type, published on 26 Aug 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2021-20809 in the wild and no public exploit code.\n\nAffected product: Six Apart Ltd. Movable Type. 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-2021-20809/ (Markdown: https://insights.sbomify.com/CVE-2021-20809/index.md)","id":"CVE-2021-20809","markdown":"https://insights.sbomify.com/CVE-2021-20809/index.md","name":"CVE-2021-20809","record":{"aliases":["GHSA-53cw-v2f6-28h4"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"Movable Type CMS","requires_auth":"none","summary":"Remote attackers can inject arbitrary scripts into Movable Type creation screens, potentially leading to session hijacking or malicious actions.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"jpcert","cpe":[{"product":"movable_type","vendor":"sixapart"}],"cvss":{"score":6.1,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"Cross-site scripting vulnerability in Create screens of Entry, Page, and Content Type of Movable Type (Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier) allows remote attackers to inject arbitrary script or HTML via unspecified vectors.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Cross-site scripting in Movable Type","id":"CVE-2021-20809","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"Cross-site scripting in Movable Type","id":"CVE-2021-20810"},"packages":[],"prev":{"headline":"Cross-site scripting in Movable Type","id":"CVE-2021-20808"},"products":["Movable Type"],"published":"2021-08-26","related":[{"cvss_score":10,"headline":"Other in n/a","id":"CVE-2009-0752","kev_date_added":null,"published":"2009-03-03"},{"cvss_score":9.8,"headline":"Command injection in Movable Type XMLRPC API","id":"CVE-2022-38078","kev_date_added":null,"published":"2022-08-24"},{"cvss_score":9.8,"headline":"Command injection in Movable Type","id":"CVE-2021-20837","kev_date_added":null,"published":"2021-10-26"},{"cvss_score":9.8,"headline":"SQL injection in n/a","id":"CVE-2016-5742","kev_date_added":null,"published":"2017-01-23"},{"cvss_score":9.3,"headline":"Code injection in Movable Type","id":"CVE-2026-25776","kev_date_added":null,"published":"2026-04-08"},{"cvss_score":8.8,"headline":"Cross-site request forgery in Movable Type","id":"CVE-2020-5576","kev_date_added":null,"published":"2020-05-14"},{"cvss_score":8.8,"headline":"File upload in Movable Type","id":"CVE-2020-5577","kev_date_added":null,"published":"2020-05-14"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":["Six Apart Ltd."]},"summary":"Remote attackers can inject arbitrary scripts into Movable Type creation screens, potentially leading to session hijacking or malicious actions.","url":"https://insights.sbomify.com/CVE-2021-20809/"}