{"id":"GHSA-4g74-7cff-xcv8","summary":"youki container escape via \"masked path\" abuse due to mount race conditions","details":"### Impact ###\n\nyouki utilizes bind mounting the container's `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.\n\nAs a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system.\n\nThis is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems.\nhttps://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2\n\n### Credits\n\nThanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings.\n\nAlso, @cyphar helped youki in finding the problem.","aliases":["CVE-2025-62161"],"modified":"2025-11-15T02:25:02Z","published":"2025-11-05T18:44:18Z","database_specific":{"github_reviewed_at":"2025-11-05T18:44:18Z","nvd_published_at":"2025-11-06T00:15:36Z","cwe_ids":["CWE-363","CWE-61"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2"},{"type":"WEB","url":"https://github.com/youki-dev/youki/security/advisories/GHSA-4g74-7cff-xcv8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-62161"},{"type":"WEB","url":"https://github.com/youki-dev/youki/commit/5886c91073b9be748bd8d5aed49c4a820548030a"},{"type":"PACKAGE","url":"https://github.com/youki-dev/youki"}],"affected":[{"package":{"name":"youki","ecosystem":"crates.io","purl":"pkg:cargo/youki"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.5.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/11/GHSA-4g74-7cff-xcv8/GHSA-4g74-7cff-xcv8.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}]}