VDB

CVE-2018-18955

CVE-2018-18955 PUBLISHED

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.

EPSS 9.57% · 93.0th percentile

Risk Scores

EPSS Score
9.57%
93.0th percentile

Affected Products

VendorProductVersions
Ubuntu:14.04:LTSlinux-azure4.15.0-1030.31~14.04.1, 4.15.0-1023.24~14.04.1, 0
Ubuntu:18.04:LTSlinux-oem4.15.0-1013.16, 4.15.0-1012.15, 4.15.0-1009.12
Ubuntu:18.04:LTSlinux-raspi24.15.0-1027.29, 4.15.0-1010.11, 4.15.0-1021.23
Ubuntu:16.04:LTSlinux-azure4.13.0-1018.21, 4.13.0-1011.14, *
Ubuntu:18.04:LTSlinux-kvm4.15.0-1020.20, 4.15.0-1016.16, 4.15.0-1012.12
Ubuntu:16.04:LTSlinux-gcp4.13.0-1006.9, 0, 4.10.0-1006.6
Ubuntu:18.04:LTSlinux-gcp4.15.0-1001.1, 4.15.0-1010.10, 4.15.0-1014.14
Ubuntu:16.04:LTSlinux-hwe4.8.0-42.45~16.04.1, 4.8.0-41.44~16.04.1, 4.8.0-39.42~16.04.1
Ubuntu:18.04:LTSlinux-aws4.15.0-1003.3, 4.15.0-1001.1, 0
Ubuntu:18.04:LTSlinux-azure4.15.0-1025.26, 4.15.0-1028.29, 4.15.0-1031.32
Ubuntu:18.04:LTSlinux4.15.0-23.25, 4.15.0-29.31, 4.15.0-32.35

Timeline

  • Nov 16, 2018 CVE Published
  • Nov 16, 2018 PoC Published
  • Nov 28, 2018 PoC Published
  • Jul 26, 2019 PoC Published
  • Apr 14, 2021 EPSS Score
  • Aug 24, 2021 EPSS Score
  • Sep 14, 2021 EPSS Score
  • Oct 26, 2021 EPSS Score
  • Dec 27, 2021 EPSS Score
  • Feb 28, 2022 EPSS Score
  • May 13, 2022 EPSS Score
  • Jul 3, 2022 EPSS Score
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