CVE-2019-15791
Reference count underflow in shiftfs
- Published
- Apr 23, 2020
- Updated
- Sep 17, 2024
- Assigning CNA
- canonical
- Evidence observed
- Nov 20, 2019
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLow · next 30 days
- Percentile
- 69.1%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
1Google Security Research · linux · Nov 20, 2019
Responsible use
Use vulnerability information only on systems you own or are authorized to test. Kitploit links to public research metadata and does not store exploit code or malicious payloads.