{"id":"GHSA-v83q-83hj-rw38","summary":"ntpd NTS client denial of service via wrongly sized cookies","details":"Two denial of service vulnerabilities were found in ntpd-rs related to the handling of NTS cookies in our client functionality. Whenever an NTS source is configured and the server behind that source is sending zero-sized cookies or cookies larger than what would fit in our buffer size, ntpd-rs would crash. Only configured NTS sources can abuse these vulnerabilities. NTP sources or third parties that are not configured cannot make use of these vulnerabilities.\n\nFor zero-sized cookies: a division by zero would force an exit when the number of new cookies that would need to be requested is calculated. In ntpd-rs 1.5.0 a check was added to prevent the division by zero.\n\nFor large cookies: while trying to send a NTP request with the cookie included, the buffer is too small to handle the cookie and an exit of ntpd-rs is forced once a write to the buffer is attempted. The memory outside the buffer would not be written to in this case. In ntpd-rs 1.5.0 a check was added that prevents accepting cookies larger than 350 bytes.\n\nUsers of older versions of ntpd-rs are recommended to update to the latest version. If an update is impossible, it is recommended to only add NTS sources to ntpd-rs that are trusted to not abuse this bug.","modified":"2025-02-28T17:46:36Z","published":"2025-02-28T17:46:36Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2025-02-28T17:46:36Z","nvd_published_at":null,"cwe_ids":["CWE-369","CWE-703"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/pendulum-project/ntpd-rs/security/advisories/GHSA-v83q-83hj-rw38"},{"type":"WEB","url":"https://github.com/pendulum-project/ntpd-rs/commit/10a103b471dae25ac598140df0c195b6531bf716"},{"type":"WEB","url":"https://github.com/pendulum-project/ntpd-rs/commit/37dd8d9a0faa03e7dfe3a4bf64953010f075c3e2"},{"type":"PACKAGE","url":"https://github.com/pendulum-project/ntpd-rs"}],"affected":[{"package":{"name":"ntpd","ecosystem":"crates.io","purl":"pkg:cargo/ntpd"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/02/GHSA-v83q-83hj-rw38/GHSA-v83q-83hj-rw38.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}