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Comrak AST node data is not validated (GHSL-2023-049)

Moderate severity GitHub Reviewed Published Mar 28, 2023 in kivikakk/comrak • Updated May 1, 2023

Package

cargo comrak (Rust)

Affected versions

< 0.17.0

Patched versions

0.17.0

Description

Impact

A Comrak AST can be constructed manually by a program instead of parsing a Markdown document with parse_document. This AST can then be converted to HTML via html::format_document_with_plugins. However, the HTML formatting code assumes that the AST is well-formed. For example, many AST notes contain [u8] fields which the formatting code assumes is valid UTF-8 data. Several bugs can be triggered if this is not the case.

Patches

0.17.0 contains adjustments to the AST, storing strings instead of unvalidated byte arrays.

Workarounds

  • Validate UTF-8 correctness of all data when assigning to &[u8] and Vec<u8> fields in the AST.

References

n/a

References

@kivikakk kivikakk published to kivikakk/comrak Mar 28, 2023
Published to the GitHub Advisory Database Mar 28, 2023
Reviewed Mar 28, 2023
Published by the National Vulnerability Database Mar 28, 2023
Last updated May 1, 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
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS score

0.462%
(76th percentile)

Weaknesses

CVE ID

CVE-2023-28631

GHSA ID

GHSA-5r3x-p7xx-x6q5

Source code

Credits

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