CVEvulnerability
CVE-2018-18955
7.0 HIGH
Official page ↗
- Status
- Modified
- Published
- 2018-11-16
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.0 ([email protected])
- 7.0 HIGH — CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- CVSS 2.0 ([email protected])
- 4.4 MEDIUM — AV:L/AC:M/Au:N/C:P/I:P/A:P
- Weaknesses
- CWE-863
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.
Affected configurations
• linux linux kernel (>= 4.15 < 4.19.2)
• canonical ubuntu linux 16.04
• canonical ubuntu linux 18.04
• canonical ubuntu linux 18.10
Related
Weakness · CWE (1)
- CWE-863 Incorrect Authorization weakness
References
- 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://bugs.chromium.org/p/project-zero/issues/detail?id=1712 Patch, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19 Patch, Vendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2 Patch, Vendor Advisory
- https://github.com/torvalds/linux/commit/d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd Patch, Vendor Advisory
- https://security.netapp.com/advisory/ntap-20190416-0003/ security.netapp.com
- https://support.f5.com/csp/article/K39103040 support.f5.com
- https://usn.ubuntu.com/3832-1/ Third Party Advisory
- https://usn.ubuntu.com/3833-1/ Third Party Advisory
- https://usn.ubuntu.com/3835-1/ Third Party Advisory
- https://usn.ubuntu.com/3836-1/ Third Party Advisory
- https://usn.ubuntu.com/3836-2/ Third Party Advisory
- https://www.exploit-db.com/exploits/45886/ Exploit, Patch, Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/45915/ Exploit, Third Party Advisory, VDB Entry
- 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://bugs.chromium.org/p/project-zero/issues/detail?id=1712 Patch, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19 Patch, Vendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2 Patch, Vendor Advisory
- https://github.com/torvalds/linux/commit/d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd Patch, Vendor Advisory
- https://security.netapp.com/advisory/ntap-20190416-0003/ security.netapp.com
- https://support.f5.com/csp/article/K39103040 support.f5.com
- https://usn.ubuntu.com/3832-1/ Third Party Advisory
- https://usn.ubuntu.com/3833-1/ Third Party Advisory
- https://usn.ubuntu.com/3835-1/ Third Party Advisory
- https://usn.ubuntu.com/3836-1/ Third Party Advisory
- https://usn.ubuntu.com/3836-2/ Third Party Advisory
- https://www.exploit-db.com/exploits/45886/ Exploit, Patch, Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/45915/ Exploit, Third Party Advisory, VDB Entry