CVE-2021-21665: 
Java vulnerability analysis and mitigation

A cross-site request forgery (CSRF) vulnerability was discovered in Jenkins XebiaLabs XL Deploy Plugin versions 10.0.1 and earlier. The vulnerability was disclosed on June 10, 2021, as part of a larger security advisory that included multiple vulnerabilities in Jenkins plugins (Jenkins Advisory).

The vulnerability stems from a form validation method that does not require POST requests in the XebiaLabs XL Deploy Plugin. This issue is part of a larger security concern (SECURITY-1982) that includes missing and incorrect permission checks. The severity is rated as High according to CVSS scoring (Jenkins Advisory).

The vulnerability allows attackers with Overall/Read permission to connect to an attacker-specified URL using attacker-specified credentials IDs obtained through another method, potentially leading to the capture of Username/password credentials stored in Jenkins (Jenkins Advisory, OSS Security).

The vulnerability can be exploited by attackers who have Overall/Read permission in Jenkins. The form validation method's lack of POST request requirement makes it susceptible to cross-site request forgery attacks (Jenkins Advisory).

The vulnerability was fixed in XebiaLabs XL Deploy Plugin version 10.0.2. The updated version requires POST requests and Overall/Administer permission for the affected form validation method. Users are advised to upgrade to this version to mitigate the vulnerability (Jenkins Advisory).