CVE Vulnerability

CVE-2018-18955

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.

4.4 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 3.4 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

7 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 1 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/torvalds/linux/commit/d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd Patch Vendor Advisory
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2 Patch Vendor Advisory
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19 Patch Vendor Advisory
https://bugs.chromium.org/p/project-zero/issues/detail?id=1712 Patch Third Party Advisory
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd Patch Vendor Advisory
http://www.securityfocus.com/bid/105941 Third Party Advisory VDB Entry
https://www.exploit-db.com/exploits/45886/ Exploit Patch
https://usn.ubuntu.com/3833-1/ Third Party Advisory
https://usn.ubuntu.com/3832-1/ Third Party Advisory
https://www.exploit-db.com/exploits/45915/ Exploit Third Party Advisory
https://usn.ubuntu.com/3836-2/ Third Party Advisory
https://usn.ubuntu.com/3836-1/ Third Party Advisory
https://usn.ubuntu.com/3835-1/ Third Party Advisory
https://support.f5.com/csp/article/K39103040
https://security.netapp.com/advisory/ntap-20190416-0003/
Configurations

Configuration 1

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
Information

Published : 2018-11-16 08:29

Updated : 2020-08-24 05:37

NVD link : CVE-2018-18955

Mitre link : CVE-2018-18955

Products Affected
No products.
CWE
CWE-863