CVE-2018-20821

Description

From CVE.org

The parsing component in LibSass through 3.5.5 allows attackers to cause a denial-of-service (uncontrolled recursion in Sass::Parser::parse_css_variable_value in parser.cpp).

Statement

This issue did not affect the versions of libsass as shipped with Red Hat Enterprise Linux 8 as the flaw was introduced in a newer version of the library.

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).

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

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score7.56.5N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneRequiredN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

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

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

Resources including CPU, memory, and stack memory could be rapidly consumed or exhausted, eventually leading to an exit or crash.

Confidentiality

Technical Impact: Read Application Data

In some cases, an application's interpreter might kill a process or thread that appears to be consuming too much resources, such as with PHP's memory_limit setting. When the interpreter kills the process/thread, it might report an error containing detailed information such as the application's installation path.

Frequently Asked Questions

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