CVE-2017-7518
Description
A flaw was found in the way the Linux KVM module processed the trap flag(TF) bit in EFLAGS during emulation of the syscall instruction, which leads to a debug exception(#DB) being raised in the guest stack. A user/process inside a guest could use this flaw to potentially escalate their privileges inside the guest. Linux guests are not affected by this.
Statement
This issue does not affect the versions of the kernel package as shipped with Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2.
This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 7. Future kernel updates for Red Hat Enterprise Linux 7 may 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 | 5.5 | 7.8 | 5.5 |
| Attack Vector | Adjacent Network | Local | Adjacent Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | High | Low |
| Integrity Impact | Low | High | Low |
| Availability Impact | Low | High | Low |
Vector
Red Hat: CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | 4.6 | N/A |
| Attack Vector | Adjacent Network | Local | N/A |
| Access Complexity | Medium | Low | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | Partial | Partial | N/A |
| Integrity Impact | Partial | Partial | N/A |
| Availability Impact | Partial | Partial | N/A |
Vector
Red Hat: AV:A/AC:M/Au:N/C:P/I:P/A:P
NVD: AV:L/AC:L/Au:N/C:P/I:P/A:P
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Access Control
Technical Impact: Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands; Read Application Data; DoS: Crash, Exit, or Restart
An attacker will be able to gain access to any resources that are allowed by the extra privileges. Common results include executing code, disabling services, and reading restricted data. New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
