Improper Handling of Highly Compressed Data (Data Amplification) Affecting fluentd package, versions <1.19.3

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the in_http and in_forward plugins when decompressing gzip-compressed data. An attacker can cause excessive memory consumption by sending a highly compressed payload that expands significantly upon decompression, potentially leading to process termination and disruption of service. This is only exploitable if the instance is exposed to untrusted networks.

This vulnerability can be mitigated by restricting network access to trusted sources using firewall rules or deploying a reverse proxy (such as Nginx) to handle gzip decompression and enforce strict body size limits before forwarding traffic.

• GitHub Advisory
• GitHub Release