{"schemaVersion":3,"id":"CVE-2019-15791","aliases":["UBUNTU-CVE-2019-15791"],"status":"published","duplicateOf":null,"title":null,"description":"In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, which then puts a reference to that file, leading to a refcount underflow.","dates":{"published":"2020-04-23T23:55:23.619Z","modified":"2024-09-17T00:11:12.912Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.8,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.8,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":4.6,"severity":"medium","vector":"AV:L/AC:L/Au:N/C:P/I:P/A:P","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":7.1,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","exploitability":4.6,"impact":8.7,"computed":true}]},"epss":{"probability":0.01317,"percentile":0.70348,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.01317},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01317,"percentile":0.70348}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01317,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01317,"percentile":0.70348}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[{"id":"47693","name":"Ubuntu 19.10 - Refcount Underflow and Type Confusion in shiftfs","source":"exploit-database","url":"https://www.exploit-db.com/exploits/47693","maturity":"poc","reliabilityScore":0.8,"verified":true,"type":"dos","platforms":["linux"],"requiresAuth":null,"exploitdb":{"verified":true,"type":"dos","platform":"linux","file":"exploits/linux/dos/47693.txt","codes":["CVE-2019-15793","CVE-2019-15792","CVE-2019-15791"]},"metasploit":null}],"exploitCount":1,"weaknesses":[{"id":"CWE-672","name":"Operation on a Resource after Expiration or Release","description":"The product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/672.html"},{"id":"CWE-191","name":"Integer Underflow (Wrap or Wraparound)","description":"The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/191.html"}],"affected":[{"vendor":"canonical","product":"ubuntu_linux","name":"ubuntu linux","label":"ubuntu_linux","ecosystem":null,"cpePart":"o","purl":null,"purlType":null,"versions":[{"text":"18.04","noFixRecorded":false,"fixedIn":null},{"text":"19.04","noFixRecorded":false,"fixedIn":null}],"versionsText":"18.04 | 19.04","eol":{"isEol":true,"eolDate":"2023-05-31T00:00:00.000Z","matchMethod":"cpe","cycle":{"name":"18.04","label":"18.04 'Bionic Beaver' (LTS)","eolFrom":"2023-05-31T00:00:00.000Z","isLts":true,"isMaintained":true,"latestVersion":"18.04.6"},"product":{"name":"ubuntu","label":"Ubuntu","category":"os"}},"hubHref":"/vendor/canonical/ubuntu_linux"},{"vendor":"ubuntu","product":"linux-azure-edge","name":"linux-azure-edge","label":"linux-azure-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-azure-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-azure-fde","name":"linux-azure-fde","label":"linux-azure-fde","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-azure-fde","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gcp-edge","name":"linux-gcp-edge","label":"linux-gcp-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gcp-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gke","name":"linux-gke","label":"linux-gke","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gke","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gkeop","name":"linux-gkeop","label":"linux-gkeop","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gkeop","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gkeop-5.15","name":"linux-gkeop-5.15","label":"linux-gkeop-5.15","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gkeop-5.15","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-hwe-edge","name":"linux-hwe-edge","label":"linux-hwe-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-hwe-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-intel-iot-realtime","name":"linux-intel-iot-realtime","label":"linux-intel-iot-realtime","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-intel-iot-realtime","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-raspi-realtime","name":"linux-raspi-realtime","label":"linux-raspi-realtime","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-raspi-realtime","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-raspi2","name":"linux-raspi2","label":"linux-raspi2","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-raspi2","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-realtime","name":"linux-realtime","label":"linux-realtime","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-realtime","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-riscv","name":"linux-riscv","label":"linux-riscv","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-riscv","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"linux","product":"linux_kernel","name":"linux kernel","label":"linux_kernel","ecosystem":null,"cpePart":"o","purl":null,"purlType":null,"versions":[{"text":"5.0","noFixRecorded":false,"fixedIn":null},{"text":"5.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"5.0 | 5.3","eol":{"isEol":null,"eolDate":null,"matchMethod":"cpe","cycle":null,"product":{"name":"linux","label":"Linux Kernel","category":"os"}},"hubHref":"/vendor/linux/linux_kernel"},{"vendor":"ubuntu","product":"shiftfs in the linux kernel","name":"Shiftfs in the Linux kernel","label":"shiftfs in the linux kernel","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 5.3.0-11.12, < 5.3 kernel*","noFixRecorded":false,"fixedIn":null},{"text":"≥ 5.0 kernel, < 5.0.0-35.38","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 5.3.0-11.12, < 5.3 kernel* | ≥ 5.0 kernel, < 5.0.0-35.38","eol":null,"hubHref":"/vendor/ubuntu/shiftfs_in_the_linux_kernel"}],"affectedCount":15,"eol":{"hasEol":true,"count":1},"references":[{"url":"https://usn.ubuntu.com/usn/usn-4183-1","label":"usn.ubuntu.com/usn/usn-4183-1","hostname":"usn.ubuntu.com","tags":["X Refsource MISC","Third Party Advisory"]},{"url":"https://usn.ubuntu.com/usn/usn-4184-1","label":"usn.ubuntu.com/usn/usn-4184-1","hostname":"usn.ubuntu.com","tags":["X Refsource MISC","Third Party Advisory"]},{"url":"https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=601a64857b3d7040ca15c39c929e6b9db3373ec1","label":"git.launchpad.net/~ubuntu-kernel/…","hostname":"git.launchpad.net","tags":["X Refsource MISC","Mailing List","Patch","Third Party Advisory"]},{"url":"https://ubuntu.com/security/CVE-2019-15791","label":"ubuntu.com/security/CVE-2019-15791","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/notices/USN-4183-1","label":"ubuntu.com/security/notices/USN-4183-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/notices/USN-4184-1","label":"ubuntu.com/security/notices/USN-4184-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2019-15791","label":"www.cve.org/CVERecord?id=CVE-2019-15791","hostname":"www.cve.org","tags":["REPORT"]}],"lineage":{"upstream":[],"downstream":["USN-4184-1"],"duplicates":[],"related":["USN-4184-1"]},"timeline":[{"kind":"published","date":"2020-04-23T23:55:23.619Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-09-17T00:11:12.912Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":41,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T04:04:31.704Z","stale":false,"partial":false}}