CVE-2020-26951

Description

From CVE.org

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass our built-in sanitizer. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

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 HatNVDcve.org
Base Score6.16.1N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionRequiredRequiredN/A
ScopeChangedChangedN/A
ConfidentialityLowLowN/A
Integrity ImpactLowLowN/A
Availability ImpactNoneNoneN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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

Understanding the Weakness (CWE)

Integrity,Other

Technical Impact: Modify Application Data; Other

Integrity checks usually use a secret key that helps authenticate the data origin. Skipping integrity checking generally opens up the possibility that new data from an invalid source can be injected.

Integrity,Other

Technical Impact: Other

Data that is parsed and used may be corrupted.

Non-Repudiation,Other

Technical Impact: Hide Activities; Other

Without a checksum check, it is impossible to determine if any changes have been made to the data after it was sent.

Acknowledgements

Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Irvan Kurniawan (@sourc7) as the original reporter.

Frequently Asked Questions

Want to get errata notifications? Sign up here.