{"answers":{"affected":"It affects 3 products.","exploited":"There is no known exploitation of CVE-2020-28935 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2020-28935 is a medium-severity path traversal vulnerability in Debian Debian Linux, published on 7 Dec 2020. 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-2020-28935 and fix it if it is affected.\n\nWhat it is: CVE-2020-28935 is a medium-severity path traversal vulnerability in Debian Debian Linux, published on 7 Dec 2020. 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-2020-28935 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-2020-28935/ (Markdown: https://insights.sbomify.com/CVE-2020-28935/index.md)","id":"CVE-2020-28935","markdown":"https://insights.sbomify.com/CVE-2020-28935/index.md","name":"CVE-2020-28935","record":{"aliases":["ALPINE-CVE-2020-28935","AZL-6931","DEBIAN-CVE-2020-28935","GHSA-q92f-7cwj-w4w5","MGASA-2021-0154","OESA-2021-1083","UBUNTU-CVE-2020-28935","openSUSE-SU-2025:15069-1"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service","data_modify"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"DNS server software","requires_auth":"low_privilege","summary":"Local attackers can exploit symlink handling in PID file creation to overwrite critical system files, causing denial of service.","user_interaction":"not_required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"NLnet Labs","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"name_server_daemon","vendor":"nlnetlabs"},{"product":"unbound","vendor":"nlnetlabs"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-59","name":"Improper Link Resolution Before File Access"}],"description":"NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.","ecosystems":["openSUSE:Tumbleweed"],"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":"Local symlink attack in Unbound and NSD","id":"CVE-2020-28935","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"debian:debian_linux","products":["debian:debian_linux","nlnetlabs:unbound"],"type":"path_traversal","year":"2020"},"n_packages":1,"n_references":5,"next":{"headline":"Missing authorization in n/a","id":"CVE-2020-28937"},"packages":[{"ecosystem":"openSUSE:Tumbleweed","fixed":["2.2.3-1.1"],"introduced":["0"],"last_affected":[],"package":"sslh","purl":"pkg:rpm/opensuse/sslh\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2025:15069-1"}],"prev":{"headline":"Cross-site request forgery in n/a","id":"CVE-2020-28931"},"products":["NSD","Unbound"],"published":"2020-12-07","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":"SUSE","prefix":"openSUSE"},{"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":"2024-09-16","vendors":["NLnet Labs"]},"summary":"Local attackers can exploit symlink handling in PID file creation to overwrite critical system files, causing denial of service.","url":"https://insights.sbomify.com/CVE-2020-28935/"}