CVE-2018-18955

CVSS V2 Medium 4.4 CVSS V3 High 7
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.
Overview
  • CVE ID
  • CVE-2018-18955
  • Assigner
  • cve@mitre.org
  • Vulnerability Status
  • Modified
  • Published Version
  • 2018-11-16T20:29:00
  • Last Modified Date
  • 2020-08-24T17:37:01
Weakness Enumerations
CWE URL
CWE-863 http://cwe.mitre.org/data/definitions/863.html
CPE Configuration (Product)
CPE Vulnerable Operator Version Start Version End
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 1 OR 4.15 4.19.2
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* 1 OR
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* 1 OR
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* 1 OR
CVSS Version 2
  • Version
  • 2.0
  • Vector String
  • AV:L/AC:M/Au:N/C:P/I:P/A:P
  • Access Vector
  • LOCAL
  • Access Compatibility
  • MEDIUM
  • Authentication
  • NONE
  • Confidentiality Impact
  • PARTIAL
  • Integrity Impact
  • PARTIAL
  • Availability Impact
  • PARTIAL
  • Base Score
  • 4.4
  • Severity
  • MEDIUM
  • Exploitability Score
  • 3.4
  • Impact Score
  • 6.4
CVSS Version 3
  • Version
  • 3.0
  • Vector String
  • CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  • Attack Vector
  • LOCAL
  • Attack Compatibility
  • HIGH
  • Privileges Required
  • LOW
  • User Interaction
  • NONE
  • Scope
  • UNCHANGED
  • Confidentiality Impact
  • HIGH
  • Availability Impact
  • HIGH
  • Base Score
  • 7
  • Base Severity
  • HIGH
  • Exploitability Score
  • 1
  • Impact Score
  • 5.9
References
Reference URL Reference Tags
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 Third Party Advisory VDB Entry
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 VDB Entry
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/
Sources
Source Name Source URL
NIST https://nvd.nist.gov/vuln/detail/CVE-2018-18955
MITRE https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-18955
History
Created Old Value New Value Data Type Notes
2022-05-10 16:30:40 Added to TrackCVE
2022-12-03 14:32:37 2018-11-16T20:29Z 2018-11-16T20:29:00 CVE Published Date updated
2022-12-03 14:32:37 2020-08-24T17:37:01 CVE Modified Date updated
2022-12-03 14:32:37 Modified Vulnerability Status updated