CVE-2021-3493

2021-04-15T00:00:00
ID UB:CVE-2021-3493
Type ubuntucve
Reporter ubuntu.com
Modified 2021-04-15T00:00:00

Description

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

Notes

Author| Note
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sbeattie | issue is specific to Ubuntu or any other distribution that patched the kernel to allow unprivileged overlay mounts, prior to the 5.11 commit (459c7c565ac36b) that permits it upstream.