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Cross-site Scripting in Parsedown

Moderate severity GitHub Reviewed Published Mar 30, 2022 to the GitHub Advisory Database • Updated Jul 15, 2023

Package

composer erusev/parsedown (Composer)

Affected versions

< 1.7.0

Patched versions

1.7.0

Description

Parsedown version prior to 1.7.0 contains a Cross Site Scripting (XSS) vulnerability in setMarkupEscaped for escaping HTML that can result in JavaScript code execution. This attack appears to be exploitable via specially crafted markdown that allows it to side step HTML escaping by breaking AST boundaries. This vulnerability appears to have been fixed in 1.7.0 and later.

References

Published to the GitHub Advisory Database Mar 30, 2022
Reviewed Mar 30, 2022
Last updated Jul 15, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS score

0.084%
(37th percentile)

Weaknesses

CVE ID

CVE-2018-1000162

GHSA ID

GHSA-qgpv-86r3-87fh

Source code

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