update snakeyaml to 1.26+ to address security vulnerability CVE-2017-18640

[brentryan]

DESCRIPTION FROM CVE
The Alias feature in SnakeYAML 1.18 allows entity expansion during a load operation, a related issue to CVE-2003-1564.

EXPLANATION
The snakeyaml package is vulnerable to YAML Entity Expansion. The load method in Yaml.class allows for entities to reference other entities. An attacker could potentially exploit this behavior by providing a YAML document with many entities that reference each other, which could take a large amount of memory to process, potentially resulting in a Denial of Service (DoS) situation.

DETECTION
The application is vulnerable by using this component with untrusted user input when the maxAliasesForCollections is set too high or settings.setAllowRecursiveKeys is set to false.

RECOMMENDATION
We recommend upgrading to a version of this component that is not vulnerable to this specific issue.

Note: If this component is included as a bundled/transitive dependency of another component, there may not be an upgrade path. In this instance, we recommend contacting the maintainers who included the vulnerable package. Alternatively, we recommend investigating alternative components or a potential mitigating control.

ROOT CAUSE
snakeyaml-1.24-android.jarorg/yaml/snakeyaml/constructor/BaseConstructor.class( , 1.26)
ADVISORIES
Project:https://bitbucket.org/asomov/snakeyaml/issues/377/allow-configuration-for-preventing-billion
CVSS DETAILS
CVE CVSS 3:7.5
CVSS Vector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

[joschi]

Refs FasterXML/jackson-dataformats-text@3e481c6

[joschi]

@brentryan Thanks for reporting this issue!

We're in contact with the Jackson team to update the SnakeYAML dependency in their module.

[joschi]

Addressed in #3227 and #3228.