CVE-2016-9604
Description
It was discovered that root can gain direct access to an internal keyring, such as '.dns_resolver' in RHEL-7 or '.builtin_trusted_keys' upstream, by joining it as its session keyring. This allows root to bypass module signature verification by adding a new public key of its own devising to the keyring.
Statement
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 as the code with the flaw is not present in this product.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 6, 7 and MRG-2. Future Linux kernel updates for the respective releases might address this issue.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.4 | 4.4 | 4.4 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | High | High | High |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | High | High | High |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
NVD: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
cve.org: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 1.2 | 2.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Access Complexity | High | Low | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | Partial | Partial | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: AV:L/AC:H/Au:N/C:N/I:P/A:N
NVD: AV:L/AC:L/Au:N/C:N/I:P/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker may be able to read sensitive information from the associated resource, such as credentials or configuration information stored in a file.
Access Control
Technical Impact: Gain Privileges or Assume Identity
An attacker may be able to modify critical properties of the associated resource to gain privileges, such as replacing a world-writable executable with a Trojan horse.
Integrity,Other
Technical Impact: Modify Application Data; Other
An attacker may be able to destroy or corrupt critical data in the associated resource, such as deletion of records from a database.
Acknowledgements
This issue was discovered by David Howells (Red Hat).
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