CVE-2021-22116 in RabbitMQ
Summary
by MITRE • 06/08/2021
RabbitMQ all versions prior to 3.8.16 are prone to a denial of service vulnerability due to improper input validation in AMQP 1.0 client connection endpoint. A malicious user can exploit the vulnerability by sending malicious AMQP messages to the target RabbitMQ instance having the AMQP 1.0 plugin enabled.
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Analysis
by VulDB Data Team • 06/11/2021
RabbitMQ versions prior to 3.8.16 contain a critical denial of service vulnerability that stems from inadequate input validation within the AMQP 1.0 client connection endpoint. This vulnerability specifically affects systems where the AMQP 1.0 plugin is enabled, creating an attack surface that malicious actors can exploit to disrupt service availability. The flaw represents a fundamental breakdown in protocol handling that allows crafted malicious messages to trigger unexpected behavior in the messaging infrastructure.
The technical implementation of this vulnerability occurs when the AMQP 1.0 plugin processes incoming messages without proper validation of message structures and content. Attackers can construct specially formatted AMQP 1.0 messages that, when processed by the vulnerable RabbitMQ instance, cause the system to enter an unstable state or terminate connections abruptly. This improper input validation creates a condition where the message processing logic fails to handle malformed or unexpected data patterns, leading to resource exhaustion or system instability. The vulnerability is classified under CWE-20 as "Improper Input Validation" and specifically manifests as a failure to properly validate and sanitize data inputs from external sources.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire messaging infrastructure. When exploited, the denial of service condition can cause RabbitMQ instances to become unresponsive, leading to cascading failures in applications that depend on message queue functionality. This vulnerability affects systems where AMQP 1.0 protocol support is enabled, which is common in enterprise environments that require interoperability with various messaging systems. The attack vector requires minimal privileges and can be executed remotely, making it particularly dangerous in production environments where continuous availability is critical.
Organizations should immediately implement mitigations by upgrading to RabbitMQ version 3.8.16 or later, which contains the necessary patches to address the input validation flaws. System administrators should also consider disabling the AMQP 1.0 plugin if it is not actively required for operations, reducing the attack surface. Network segmentation and access controls should be implemented to limit exposure of RabbitMQ instances to untrusted networks. Additionally, monitoring should be enhanced to detect unusual connection patterns or message processing behaviors that may indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1499.004 for "Network Denial of Service" and represents a common pattern of protocol-based attacks that target messaging systems in enterprise environments.