An issue was identified by Elastic whereby sensitive information is recorded in Logstash logs under specific circumstances. The prerequisites for the manifestation of this issue are: * Logstash is configured to log in JSON format https://www.elastic.co/guide/en/logstash/current/running-logstash-command-line.html , which is not the default logging format. * Sensitive data is stored in the Logstash keystore and referenced as a variable in Logstash configuration.

The Luxas98/logstash-management-api repository through 2020-05-04 on GitHub allows absolute path traversal because the Flask send_file function is used unsafely.

In Logstash versions after 6.4.0 and before 6.8.15 and 7.12.0 a TLS certificate validation flaw was found in the monitoring feature. When specifying a trusted server CA certificate Logstash would not properly verify the certificate returned by the monitoring server. This could result in a man in the middle style attack against the Logstash monitoring data.

Jenkins Logstash Plugin 2.3.1 and earlier transmits configured credentials in plain text as part of its global Jenkins configuration form, potentially resulting in their exposure.

Logstash versions before 7.4.1 and 6.8.4 contain a denial of service flaw in the Logstash Beats input plugin. An unauthenticated user who is able to connect to the port the Logstash beats input could send a specially crafted network packet that would cause Logstash to stop responding.

A sensitive data disclosure flaw was found in the way Logstash versions before 5.6.15 and 6.6.1 logs malformed URLs. If a malformed URL is specified as part of the Logstash configuration, the credentials for the URL could be inadvertently logged as part of the error message.

X-Pack Machine Learning versions before 6.2.4 and 5.6.9 had a cross-site scripting (XSS) vulnerability. If an attacker is able to inject data into an index that has a ML job running against it, then when another user views the results of the ML job it could allow the attacker to obtain sensitive information from or perform destructive actions on behalf of that other ML user.

X-Pack Machine Learning versions before 6.2.4 and 5.6.9 had a cross-site scripting (XSS) vulnerability. Users with manage_ml permissions could create jobs containing malicious data as part of their configuration that could allow the attacker to obtain sensitive information from or perform destructive actions on behalf of other ML users viewing the results of the jobs.

When logging warnings regarding deprecated settings, Logstash before 5.6.6 and 6.x before 6.1.2 could inadvertently log sensitive information.

The init script in the Gentoo app-admin/logstash-bin package before 5.5.3 and 5.6.x before 5.6.1 has "chown -R" calls for user-writable directory trees, which allows local users to gain privileges by leveraging access to a $LS_USER account for creation of a hard link.