Mishandling of file-system uid/gid with namespaces in shiftfs
33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 6.5epss 0.7%
from disclosure to weapon0 days
Published on NVDApr 23
1st PoCNov 20
exploitation probability
0.7%top 51% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Affected products
Ubuntu · Shiftfs in the Linux kernelpublic PoCs found — 1✓ VexDay Proof
exploitdb✓ VexDay Proofwww.exploit-db.com/exploits/47693⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.