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CWL Viewer: deserialization of untrusted data can lead to complete takeover by an attacker

Critical
mr-c published GHSA-7g7j-f5g3-fqp7 Sep 30, 2021

Package

cwlviewer (GitHub)

Affected versions

=< 1.3.0

Patched versions

1.4.0

Description

Impact

What kind of vulnerability is it? Deserialization of Untrusted Data

Who is impacted? Anyone running cwlviewer older than f6066f0 (dated 2021-09-30)

Patches

Patched in f6066f0 , released as part of cwlviewer v1.4

The instance at https://view.commonwl.org has been updated as well

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading? No. The SnakeYaml constructor, by default, allows any data to be parsed. To fix the issue the object needs to be created with a SafeConstructor object, as seen in the patch.

References

Are there any links users can visit to find out more? Analysis of the SnakeYaml deserialization in Java Security

For more information

If you have any questions or comments about this advisory:

Severity

Critical

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
High
Availability
High

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:H/A:H

CVE ID

CVE-2021-41110

Weaknesses

Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Learn more on MITRE.

Credits