Mishandling of file-system uid/gid with namespaces in shiftfs (Ubuntu Shiftfs in the Linux kernel)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.69 % · percentile 53 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- canonical
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-538 — Insertion of Sensitive Information into Externally-Accessible File or Directory
- CWE-276 — Incorrect Default Permissions
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N | canonical |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N | NVD · security@ubuntu.com (Secondary) |
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | MEDIUM 4.6 | AV:L/AC:L/Au:N/C:P/I:P/A:P | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2019-6716
- GCVE · GCVE-0-2019-15793
CERT-FR advisories
- CERTFR-2019-AVI-555 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:5.0:*:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:5.3:*:*:*:*:*:*:*cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Ubuntu · Shiftfs in the Linux kernel | affected 5.3.0-11.12 < 5.3 kernel* ; affected 5.0 kernel < 5.0.0-35.38 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |