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.
CVSS Details
- CVSS 3.1 Base Score: 7
- CVSS 3.0 Vector: (CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Jul 30, 2024 | Nov 16, 2018 |
| Ubuntu | — | Upgrade linux-image-lowlatencyUpgrade linux-image-raspi2Upgrade linux-image-generic-lpaeUpgrade linux-image-gkeUpgrade linux-image-4.15.0-42-genericUpgrade linux-image-awsUpgrade linux-image-genericUpgrade linux-image-gcpUpgrade linux-image-generic-lpae-hwe-16.04Upgrade linux-image-4.18.0-12-snapdragonUpgrade linux-image-4.15.0-42-lowlatencyUpgrade linux-image-4.18.0-1005-kvmUpgrade linux-image-4.18.0-1007-raspi2Upgrade linux-image-4.18.0-1004-gcpUpgrade linux-image-4.15.0-1025-gcpUpgrade linux-image-generic-hwe-16.04Upgrade linux-image-oemUpgrade linux-image-4.18.0-12-genericUpgrade linux-image-4.15.0-1029-awsUpgrade linux-image-4.18.0-12-lowlatencyUpgrade linux-image-4.18.0-12-generic-lpaeUpgrade linux-image-snapdragonUpgrade linux-image-4.18.0-1006-awsUpgrade linux-image-4.15.0-1029-raspi2Upgrade linux-image-4.15.0-1027-kvmUpgrade linux-image-lowlatency-hwe-16.04Upgrade linux-image-4.15.0-42-snapdragonUpgrade linux-image-4.15.0-42-generic-lpaeUpgrade linux-image-kvm | Dec 7, 2018 | Nov 16, 2018 |
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