The Linux kernel through 3.17.4 does not properly restrict dropping of supplemental group memberships in certain namespace scenarios, which allows local users to bypass intended file permissions by leveraging a POSIX ACL containing an entry for the group category that is more restrictive than the entry for the other category, aka a "negative groups" issue, related to kernel/groups.c, kernel/uid16.c, and kernel/user_namespace.c.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2014-8989 from the MITRE CVE dictionary dictionary and NIST NVD.
Not vulnerable. This issue does not affect the versions of the kernel package as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 3.6 |
|---|---|
| Base Metrics | AV:L/AC:L/Au:N/C:P/I:P/A:N |
| Access Vector | Local |
| Access Complexity | Low |
| Authentication | None |
| Confidentiality Impact | Partial |
| Integrity Impact | Partial |
| Availability Impact | None |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | kernel | Not affected |
| Red Hat Enterprise Linux 7 | kernel | Not affected |
| Red Hat Enterprise Linux 6 | kernel | Not affected |
| Red Hat Enterprise Linux 5 | kernel | Not affected |
Vulmon