{"id":"CVE-2018-6557","aliases":["EUVD-2018-18309","GHSA-vfrm-87wr-xvjf","UBUNTU-CVE-2018-6557","USN-3748-1"],"status":"published","title":"Insecure temporary file use in base-files","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","severity":{"version":"3.1","score":7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.00373,"percentile":0.31425,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-59"],"published":"2018-08-21T00:00:00Z","modified":"2026-06-17T02:02:01Z","fixes":[{"ecosystem":"Ubuntu:18.04:LTS","package":"base-files","fixed_in":["10.1ubuntu2.2"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"base-files","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.1ubuntu2.2"}]}],"versions":["9.6ubuntu102","10ubuntu1","10.1ubuntu1","10.1ubuntu2","10.1ubuntu2.1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"base-files","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.1ubuntu2.2"}]}],"versions":["9.6ubuntu102","10ubuntu1","10.1ubuntu1","10.1ubuntu2","10.1ubuntu2.1"]}],"products":[{"vendor":"base-files_project","product":"base-files"},{"vendor":"canonical","product":"ubuntu_linux"},{"vendor":"ubuntu","product":"base-files"}],"references":[{"url":"https://usn.ubuntu.com/3748-1/","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred","Vendor Advisory"]},{"url":"http://www.securitytracker.com/id/1041530","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred","Broken Link","Third Party Advisory","VDB Entry"]},{"url":"http://www.securityfocus.com/bid/105148","tags":["vdb-entry","x_refsource_BID","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-6557"},{"url":"https://github.com/advisories/GHSA-vfrm-87wr-xvjf"},{"url":"https://ubuntu.com/security/CVE-2018-6557","tags":["report"]},{"url":"http://www.sbosnet.nl/","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-3748-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2018-6557","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2018-6557","title":"Insecure temporary file use in base-files","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","status":"published","published":"2018-08-21T16:00:00Z","modified":"2024-09-16T18:24:32.413Z","updated_at":"2026-11-02T14:35:05.961936Z"}],"euvd":[{"id":"EUVD-2018-18309","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","status":"published","published":"2018-08-21T16:00:00Z","modified":"2024-09-16T18:24:32Z","updated_at":"2026-11-03T00:55:32.945265Z"}],"ghsa":[{"id":"GHSA-vfrm-87wr-xvjf","title":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and...","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","status":"published","published":"2022-05-14T01:57:31Z","modified":"2023-02-03T05:04:14Z","cvss":[{"version":"3.0","score":7,"vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T14:53:30.880998Z"}],"nvd":[{"id":"CVE-2018-6557","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","status":"published","published":"2018-08-21T16:29:00.637Z","modified":"2026-06-17T02:02:01.367Z","cvss":[{"version":"3.1","score":7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.4,"vector":"AV:L/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T14:04:36.842579Z"}],"osv":[{"id":"UBUNTU-CVE-2018-6557","description":"The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.","status":"published","published":"2018-08-21T00:00:00Z","modified":"2026-02-04T04:11:48.122021Z","cvss":[{"version":"3.1","score":7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"},{"version":"3.0","score":7,"vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:18.772093Z"},{"id":"USN-3748-1","title":"base-files vulnerability","description":"Sander Bos discovered that the MOTD update script incorrectly handled\ntemporary files. A local attacker could use this issue to cause a denial of\nservice, or possibly escalate privileges if kernel symlink restrictions\nwere disabled.\n","status":"published","published":"2018-08-21T12:20:12Z","modified":"2026-02-10T04:41:23Z","updated_at":"2026-11-02T16:58:14.019824Z"}]}}