CVE-2017-18043

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DescriptionAdditional informationAffected PackagesCVSS Score DetailsWeakness (CWE)AcknowledgementsFAQ

Description

The CVE Program describes this issue as:

Integer overflow in the macro ROUND_UP (n, d) in Quick Emulator (Qemu) allows a user to cause a denial of service (Qemu process crash).

Additional information

  • Bugzilla 1536377: Qemu: integer overflow in ROUND_UP macro could result in DoS
  • CWE-190: Integer Overflow or Wraparound
  • FAQ: Frequently asked questions about CVE-2017-18043

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).

CVSS v3

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

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

2.8

5.5

Attack Vector

Local

Local

Attack Complexity

High

Low

Privileges Required

Low

Low

User Interaction

None

None

Scope

Changed

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

Low

High

CVSS v3 Vector

Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:L

NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v2

Understanding the Weakness (CWE)

CWE-190

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability

This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.

Integrity

Technical Impact: Modify Memory

If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.

Confidentiality,Availability,Access Control

Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism

This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.

Availability,Other

Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.

Access Control

Technical Impact: Bypass Protection Mechanism

If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.

Acknowledgements

This issue was discovered by Eric Blake (Red Hat Inc.).

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?

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