{"id":"GHSA-jv9c-w74q-6762","summary":"Insecure permissions on build temporary rootfs in Singularity","details":"### Impact\n\nInsecure permissions on temporary directories used in explicit and implicit container build operations.\n\nWhen a Singularity command that results in a container build operation is executed, it is possible for a user with access to the system to read the contents of the image during the build. Additionally, if the image contains a world-writable file or directory, it is possible for a user to inject arbitrary content into the running build, which in certain circumstances may enable arbitrary code execution during the build and/or when the built container is run.\n\n### Patches\n\nThis issue is addressed in Singularity 3.6.3.\n\nAll users are advised to upgrade to 3.6.3.\n\n### Workarounds\n\nThe issue is mitigated if `TMPDIR` is set to a location that is only accessible to the user, as any subdirectories directly under `TMPDIR` cannot then be accessed by others. However, this is difficult to enforce so it is not recommended to rely on this as a mitigation.\n\n### For more information\n\nGeneral questions about the impact of the advisory / changes made in the 3.6.0 release can be asked in the:\n\n* [Singularity Slack Channel](https://bit.ly/2m0g3lX)\n* [Singularity Mailing List](https://groups.google.com/a/lbl.gov/forum/??sdf%7Csort:date#!forum/singularity)\n\nAny sensitive security concerns should be directed to: security@sylabs.io\n\nSee our Security Policy here: https://sylabs.io/security-policy","aliases":["CVE-2020-25040"],"modified":"2026-05-07T05:02:15.854919486Z","published":"2021-05-24T16:56:23Z","database_specific":{"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2021-05-24T16:53:16Z","nvd_published_at":"2020-09-16T18:15:00Z","cwe_ids":["CWE-668","CWE-732"]},"references":[{"type":"WEB","url":"https://github.com/hpcng/singularity/security/advisories/GHSA-jv9c-w74q-6762"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-25040"},{"type":"WEB","url":"https://medium.com/sylabs"},{"type":"WEB","url":"http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00070.html"},{"type":"WEB","url":"http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00088.html"}],"affected":[{"package":{"name":"github.com/sylabs/singularity","ecosystem":"Go","purl":"pkg:golang/github.com/sylabs/singularity"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.6.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/05/GHSA-jv9c-w74q-6762/GHSA-jv9c-w74q-6762.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}