CVE-2016-2198

Public on

Last Modified: UTC

Description

A NULL pointer dereference flaw was found in the QEMU emulator built with USB EHCI emulation support. The flaw could occur when an application attempts to write to EHCI-capability registers. A privileged user inside a quest could exploit this flaw to crash the QEMU process instance (denial of service).

A NULL pointer dereference flaw was found in the QEMU emulator built with USB EHCI emulation support. The flaw could occur when an application attempts to write to EHCI-capability registers. A privileged user inside a quest could exploit this flaw to crash the QEMU process instance (denial of service).

Statement

This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.

This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.

Additional information

  • Bugzilla 1301643: Qemu: usb: ehci null pointer dereference in ehci_caps_write
  • CWE-476: NULL Pointer Dereference
  • FAQ: Frequently asked questions about CVE-2016-2198

Common Vulnerability Scoring System (CVSS) Score Details

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).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v2 Score Breakdown
Red HatNVD

CVSS v2 Base Score

2.3

2.1

Attack Vector

Adjacent Network

Local

Access Complexity

Medium

Low

Authentication

Single

None

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

Partial

Partial

CVSS v2 Vector

Red Hat: AV:A/AC:M/Au:S/C:N/I:N/A:P

NVD: AV:L/AC:L/Au:N/C:N/I:N/A:P

Understanding the Weakness (CWE)

CWE-476

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Acknowledgements

Red Hat would like to thank Zuozhi Fzz (Alibaba Inc.) for reporting this issue.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

Want to get errata notifications? Sign up here.