Description
In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-3832-1 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-3833-1 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-3835-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-3836-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-3836-2 | Linux kernel (HWE) vulnerabilities |
References
History
No history.
Status: PUBLISHED
Assigner: mitre
Published:
Updated: 2024-08-05T11:23:08.917Z
Reserved: 2018-11-05T00:00:00.000Z
Link: CVE-2018-18955
No data.
Status : Modified
Published: 2018-11-16T20:29:00.233
Modified: 2024-11-21T03:56:56.423
Link: CVE-2018-18955
OpenCVE Enrichment
No data.
Ubuntu USN