CVE-2019-15793
A local attacker could use this to possibly bypass discretionary access control permissions.
Does this matter?
A public exploit is published in Exploit-DB (verified) and the impact is high, while EPSS rates exploitation at 0.7%. Anyone can run this; patch or mitigate before the next change window and check exposed instances for signs of use.
Description
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.69% probability · 52th percentile
- Public exploits
- 1 in Exploit-DB · verified · first 20 November 2019
- CISA KEV
- Not listed
- Weakness
- CWE-538, CWE-276
- Affected
- linux/linux kernel · canonical/ubuntu linux
- Source
- security@ubuntu.com
EPSS 0.7% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bbMailing List, Patch, Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bbMailing List, Patch, Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.