CVE-2018-18955
Summary
| CVE | CVE-2018-18955 |
|---|---|
| State | PUBLIC |
| Assigner | [email protected] |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2018-11-16 20:29:00 UTC |
| Updated | 2020-08-24 17:37:00 UTC |
| 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. |
Risk And Classification
Problem Types: CWE-863
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Canonical | Ubuntu Linux | 16.04 | All | All | All |
| Operating System | Canonical | Ubuntu Linux | 18.04 | All | All | All |
| Operating System | Canonical | Ubuntu Linux | 18.10 | All | All | All |
| Operating System | Canonical | Ubuntu Linux | 16.04 | All | All | All |
| Operating System | Canonical | Ubuntu Linux | 18.04 | All | All | All |
| Operating System | Canonical | Ubuntu Linux | 18.10 | All | All | All |
| Operating System | Linux | Linux Kernel | All | All | All | All |
| Operating System | Linux | Linux Kernel | All | All | All | All |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| 1712 - Linux: broken uid/gid mapping for nested user namespaces with >5 ranges - project-zero - Monorail | MISC | bugs.chromium.org | Patch, Third Party Advisory |
| USN-3832-1: Linux kernel (AWS) vulnerabilities | Ubuntu security notices | UBUNTU | usn.ubuntu.com | Third Party Advisory |
| support.f5.com/csp/article/K39103040 | CONFIRM | support.f5.com | |
| USN-3835-1: Linux kernel vulnerabilities | Ubuntu security notices | UBUNTU | usn.ubuntu.com | Third Party Advisory |
| kernel/git/torvalds/linux.git - Linux kernel source tree | MISC | git.kernel.org | Patch, Vendor Advisory |
| Linux - Nested User Namespace idmap Limit Local Privilege Escalation (Metasploit) - Linux local Exploit | EXPLOIT-DB | www.exploit-db.com | Exploit, Third Party Advisory, VDB Entry |
| cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19 | MISC | cdn.kernel.org | Patch, Vendor Advisory |
| CVE-2018-18955 Linux Kernel Vulnerability in NetApp Products | NetApp Product Security | CONFIRM | security.netapp.com | |
| cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2 | MISC | cdn.kernel.org | Patch, Vendor Advisory |
| userns: also map extents in the reverse map to kernel IDs · torvalds/linux@d2f007d · GitHub | MISC | github.com | Patch, Vendor Advisory |
| USN-3836-1: Linux kernel vulnerabilities | Ubuntu security notices | UBUNTU | usn.ubuntu.com | Third Party Advisory |
| Linux - Broken uid/gid Mapping for Nested User Namespaces - Linux local Exploit | EXPLOIT-DB | www.exploit-db.com | Exploit, Patch, Third Party Advisory, VDB Entry |
| USN-3836-2: Linux kernel (HWE) vulnerabilities | Ubuntu security notices | UBUNTU | usn.ubuntu.com | Third Party Advisory |
| USN-3833-1: Linux kernel (AWS) vulnerabilities | Ubuntu security notices | UBUNTU | usn.ubuntu.com | Third Party Advisory |
| Linux Kernel CVE-2018-18955 Local Privilege Escalation Vulnerability | BID | www.securityfocus.com | Third Party Advisory, VDB Entry |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.