CVE-2020-2180: 
Java vulnerability analysis and mitigation

AWS SAM Plugin 1.2.2 and earlier contains a high-severity vulnerability (CVE-2020-2180) related to its YAML parser configuration. The vulnerability was disclosed on April 16, 2020, affecting the Jenkins AWS SAM Plugin versions up to and including 1.2.2. This security issue was identified as SECURITY-1736 in the Jenkins security advisory system (Jenkins Advisory, OSS Security).

The vulnerability stems from the plugin's failure to configure its YAML parser to prevent the instantiation of arbitrary types. This misconfiguration in the YAML parser implementation could allow for unsafe deserialization of untrusted data, classified under CWE-502 (Deserialization of Untrusted Data). The vulnerability has been assigned a CVSS v3.1 Base Score of 8.8 (HIGH), with the vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

The vulnerability results in a remote code execution (RCE) capability that can be exploited by users who have either the ability to configure a job or control the contents of a previously configured 'AWS SAM deploy application' build step's YAML SAM template file (template.yaml or equivalent) (Jenkins Advisory).

The vulnerability is exploitable by users with job configuration permissions or access to modify the YAML SAM template files used in the build process. The attack vector requires low complexity and only low privileges, making it relatively straightforward to exploit for authenticated users with the necessary permissions (NVD).

The vulnerability has been fixed in AWS SAM Plugin version 1.2.3, which properly configures its YAML parser to only instantiate safe types. Users are strongly advised to upgrade to this version or later to address the security issue (Jenkins Advisory).