{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-48239 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2023-48239 yet. Limit exposure of the affected software until one is available.","what":"CVE-2023-48239 is a high-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 21 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-48239 and fix it if it is affected.\n\nWhat it is: CVE-2023-48239 is a high-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 21 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-48239 in the wild and no public exploit code.\n\nAffected product: Nextcloud Nextcloud Server. 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-2023-48239/ (Markdown: https://insights.sbomify.com/CVE-2023-48239/index.md)","id":"CVE-2023-48239","markdown":"https://insights.sbomify.com/CVE-2023-48239/index.md","name":"CVE-2023-48239","record":{"aliases":["GHSA-f962-hw26-g267"],"analysis":{"component_type":"cloud_service","fix_type":"patch","impacts":["denial_of_service","data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"Nextcloud Server","requires_auth":"low_privilege","summary":"A malicious user can modify external storage configurations to make them inaccessible to other users, causing denial of service.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"nextcloud_server","vendor":"nextcloud"}],"cvss":{"score":8.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H","version":"3.1"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"description":"Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Server and starting in version 20.0.0 and prior to versions 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Enterprise Server, a malicious user could update any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud Server 25.0.13, 26.0.8, and 27.1.3 and Nextcloud Enterprise Server is upgraded to 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 contain a patch for this issue. As a workaround, disable app files_external. This workaround also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.","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":"Nextcloud Server users can make external storage mount points inaccessible for other users","id":"CVE-2023-48239","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"nextcloud:nextcloud_server","products":["nextcloud:nextcloud_server"],"type":"missing_authorization","year":"2023"},"n_packages":0,"n_references":3,"next":{"headline":"XWiki Platform sends cookies to external images in rendered diff and is vulnerable to server side request forgery","id":"CVE-2023-48240"},"packages":[],"prev":{"headline":"JWT Algorithm Confusion in json-web-token library","id":"CVE-2023-48238"},"products":["security-advisories"],"published":"2023-11-21","related":[{"cvss_score":9.3,"headline":"Preview generation used third-party library not suited for user-generated content in Nextcloud server","id":"CVE-2021-32802","kev_date_added":null,"published":"2021-09-07"},{"cvss_score":9.1,"headline":"Scope of workflow operations is not validated in nextcloud server","id":"CVE-2023-26482","kev_date_added":null,"published":"2023-03-30"},{"cvss_score":8.8,"headline":"Auth bypass in Nextcloud Server","id":"CVE-2018-3775","kev_date_added":null,"published":"2018-08-12"},{"cvss_score":8.7,"headline":"Nextcloud Server password reset endpoint is not brute force protected","id":"CVE-2023-35172","kev_date_added":null,"published":"2023-06-23"},{"cvss_score":8.7,"headline":"Nextcloud Server's brute force protection allows someone to send more requests than intended","id":"CVE-2023-32320","kev_date_added":null,"published":"2023-06-22"},{"cvss_score":8.6,"headline":"Trusted servers exchange can be triggered by attacker","id":"CVE-2021-32656","kev_date_added":null,"published":"2021-06-01"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-06-10","vendors":["nextcloud"]},"summary":"A malicious user can modify external storage configurations to make them inaccessible to other users, causing denial of service.","url":"https://insights.sbomify.com/CVE-2023-48239/"}