CVE-2019-15793: Mishandling of file-system uid/gid with namespaces in shiftfs
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 inituserns, whereas they should have been translated into the suserns 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 suserns. A local attacker could use this to possibly bypass discretionary access control permissions.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.187-1Fixed in 6.12.107-1Fixed in 7.1.13-1 - Upgrade
Upgrade
Linux kernel shiftfs (Ubuntu kernel 5.0/5.3 series, non-upstream patch)to a version that resolves this vulnerability.Fixed in 5.0 - Upgrade
Upgrade
Linux kernel shiftfs (Ubuntu kernel 5.0/5.3 series, non-upstream patch)to a version that resolves this vulnerability.Fixed in 5.3
Event History
Frequently Asked Questions
What is the vulnerability ID for this issue?
The vulnerability ID for this issue is CVE-2019-15793.
What is the affected software for this vulnerability?
The affected software for this vulnerability includes the Ubuntu 5.0 and 5.3 kernel series.
What is the severity of CVE-2019-15793?
The severity of CVE-2019-15793 is not specified.
How can I fix CVE-2019-15793?
To fix CVE-2019-15793, it is recommended to update to the latest version of the Ubuntu kernel series affected by this vulnerability.
Where can I find more information about CVE-2019-15793?
You can find more information about CVE-2019-15793 in the references provided: [reference](https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bb) [reference](https://usn.ubuntu.com/usn/usn-4183-1) [reference](https://usn.ubuntu.com/usn/usn-4184-1)