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-generic-lpaeUpgrade linux-image-4.18.0-1005-kvmUpgrade linux-image-4.15.0-42-lowlatencyUpgrade linux-image-4.18.0-1007-raspi2Upgrade linux-image-4.18.0-1004-gcpUpgrade linux-image-lowlatencyUpgrade linux-image-raspi2Upgrade linux-image-generic-hwe-16.04Upgrade linux-image-gkeUpgrade linux-image-genericUpgrade linux-image-4.15.0-42-genericUpgrade linux-image-gcpUpgrade linux-image-awsUpgrade linux-image-generic-lpae-hwe-16.04Upgrade linux-image-4.15.0-1025-gcpUpgrade linux-image-4.18.0-12-snapdragonUpgrade linux-image-snapdragonUpgrade linux-image-4.15.0-1029-raspi2Upgrade linux-image-4.18.0-12-genericUpgrade linux-image-4.18.0-12-generic-lpaeUpgrade linux-image-oemUpgrade linux-image-kvmUpgrade linux-image-4.18.0-12-lowlatencyUpgrade linux-image-4.15.0-42-snapdragonUpgrade linux-image-4.15.0-1029-awsUpgrade linux-image-4.18.0-1006-awsUpgrade linux-image-lowlatency-hwe-16.04Upgrade linux-image-4.15.0-42-generic-lpaeUpgrade linux-image-4.15.0-1027-kvm | Dec 7, 2018 | Nov 16, 2018 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub