{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-29503 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-29503 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-29503 is a high-severity cross-site scripting vulnerability in hedgedoc, published on 19 May 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-2021-29503 and fix it if it is affected.\n\nWhat it is: CVE-2021-29503 is a high-severity cross-site scripting vulnerability in hedgedoc, published on 19 May 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-2021-29503 in the wild and no public exploit code.\n\nAffected product: hedgedoc. 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-2021-29503/ (Markdown: https://insights.sbomify.com/CVE-2021-29503/index.md)","id":"CVE-2021-29503","markdown":"https://insights.sbomify.com/CVE-2021-29503/index.md","name":"CVE-2021-29503","record":{"aliases":["GHSA-gjg7-4j2h-94fq"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"HedgeDoc markdown platform","requires_auth":"none","summary":"Attackers can inject JavaScript via YAML metadata in HedgeDoc notes, potentially leading to code execution or account takeover.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"hedgedoc","vendor":"hedgedoc"}],"cvss":{"score":8.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-80","name":"Improper Neutralization of Script-Related HTML Tags in a Web Page"}],"description":"HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a note can embed HTML tags in the Open Graph metadata section of the note, resulting in the frontend rendering the script tag as part of the `\u003chead\u003e` section. Unless your instance prevents guests from editing notes, this vulnerability allows unauthenticated attackers to inject JavaScript into notes that allow guest edits. If your instance prevents guests from editing notes, this vulnerability allows authenticated attackers to inject JavaScript into any note pages they have write-access to. This vulnerability is patched in version 1.8.2. As a workaround, one can disable guest edits until the next update.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Improper Neutralization of Script-Related HTML Tags in Notes","id":"CVE-2021-29503","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"Improper Certificate Validation in WP-CLI framework","id":"CVE-2021-29504"},"packages":[],"prev":{"headline":"Remote code execution in the WarnSystem module of Laggrons-Dumb-Cogs","id":"CVE-2021-29502"},"products":["hedgedoc"],"published":"2021-05-19","related":[{"cvss_score":10,"headline":"PDF export allows arbitrary file reads","id":"CVE-2021-29475","kev_date_added":null,"published":"2021-04-26"},{"cvss_score":8.7,"headline":"Stored XSS in mermaid diagrams","id":"CVE-2020-26287","kev_date_added":null,"published":"2020-12-28"},{"cvss_score":8.1,"headline":"XSS vector in slide mode speaker-view","id":"CVE-2021-39175","kev_date_added":null,"published":"2021-08-30"},{"cvss_score":7.5,"headline":"Arbitary file upload","id":"CVE-2020-26286","kev_date_added":null,"published":"2020-12-28"},{"cvss_score":7.4,"headline":"Stored XSS in slide mode","id":"CVE-2021-21259","kev_date_added":null,"published":"2021-01-22"},{"cvss_score":6.5,"headline":"MySQL \u0026 free URL mode allows to hide existing notes in hedgedoc","id":"CVE-2024-45308","kev_date_added":null,"published":"2024-09-02"}],"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":["hedgedoc"]},"summary":"Attackers can inject JavaScript via YAML metadata in HedgeDoc notes, potentially leading to code execution or account takeover.","url":"https://insights.sbomify.com/CVE-2021-29503/"}