CVE-2023-23899: 
WordPress vulnerability analysis and mitigation

Git server Plugin for Jenkins, version 99.va0826abcdfad and earlier, contains an arbitrary file read vulnerability identified as CVE-2023-23899. The vulnerability was discovered in January 2024 and affects the Git server Plugin's command argument parsing functionality (Jenkins Advisory).

The vulnerability exists in the Git server Plugin's use of the args4j library for parsing command arguments and options on the Jenkins controller when processing Git commands received via SSH. The plugin does not disable a feature that replaces an @ character followed by a file path in an argument with the file's contents (expandAtFiles). This feature is enabled by default, allowing attackers with Overall/Read permission to read the first two lines of arbitrary files on the Jenkins controller file system using the default character encoding of the Jenkins controller process (Jenkins Advisory).

The vulnerability allows attackers with Overall/Read permission to read sensitive files on the Jenkins controller. The impact is considered high as it could potentially lead to exposure of sensitive information and, under certain conditions, could contribute to remote code execution attacks (Jenkins Advisory).

The vulnerability has been fixed in Git server Plugin version 99.101.v720e86326c09. As a workaround, administrators can navigate to Manage Jenkins » Security and ensure that the SSHD Port setting in the SSH Server section is set to Disable. This disables access to Git repositories hosted by Jenkins via SSH (Jenkins Advisory).