#VU15836 Privilege escalation in Linux kernel - CVE-2018-18955
Published: November 13, 2018 / Updated: May 23, 2022
Vulnerability identifier: #VU15836
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear
CVE-ID: CVE-2018-18955
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a local attacker to gain elevated privileges on a targeted system.
The weakness exists due to the map_write() function, as defined in the kernel/user_namespace.c source code file, improperly handles nested user namespaces that have more than five user identifier (UID) or group identifier (GID) ranges. A local attacker with CAP_SYS_ADMIN capabilities in a targeted user namespace can access the system and execute an application that submits malicious input to bypass access controls outside the user namespace and gain elevated privileges on the system.
Remediation
The vulnerability has been fixed in the versions 4.18.19, 4.19.2.