{"api_version":"1","generated_at":"2026-04-23T02:36:17+00:00","cve":"CVE-2023-2640","urls":{"html":"https://cve.report/CVE-2023-2640","api":"https://cve.report/api/cve/CVE-2023-2640.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2023-2640","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-2640"},"summary":{"title":"CVE-2023-2640","description":"On Ubuntu kernels carrying both c914c0e27eb0 and \"UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs\", an unprivileged user may set privileged extended attributes on the mounted files, leading them to be set on the upper files without the appropriate security checks.","state":"PUBLIC","assigner":"security@ubuntu.com","published_at":"2023-07-26 02:15:00","updated_at":"2023-08-03 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not needed, disable the ability for unprivileged users\nto create namespaces. To do this temporarily, do:\n  sudo sysctl -w kernel.unprivileged_userns_clone=0\nTo disable across reboots, do:\n  echo kernel.unprivileged_userns_clone=0 | \\\n  sudo tee /etc/sysctl.d/99-disable-unpriv-userns.conf"}],"credits":[{"lang":"en","value":"Stonejiajia"},{"lang":"en","value":"Shir Tamari"},{"lang":"en","value":"Sagi Tzadik"}],"impact":{"cvss":[{"version":"3.1","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"}]}},"nvd":{"publishedDate":"2023-07-26 02:15:00","lastModifiedDate":"2023-08-03 15:10:00","problem_types":["CWE-863"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:canonical:ubuntu_linux:23.04:*:*:*:*:*:*:*","cpe_name":[]}]}]}},"legacy_mitre":{"record":null,"notes":[]}}}