CVE-2017-15535 in MongoDB
Summary
by MITRE
MongoDB 3.4.x before 3.4.10, and 3.5.x-development, has a disabled-by-default configuration setting, networkMessageCompressors (aka wire protocol compression), which exposes a vulnerability when enabled that could be exploited by a malicious attacker to deny service or modify memory.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-15535 affects MongoDB versions 3.4.x prior to 3.4.10 and 3.5.x development branches, representing a critical security flaw in the database's network protocol handling. This issue stems from a configuration setting named networkMessageCompressors, which controls wire protocol compression functionality within the MongoDB server. The vulnerability becomes exploitable when this otherwise disabled-by-default setting is enabled, creating a dangerous attack surface that could be leveraged by malicious actors to compromise system integrity and availability.
The technical flaw manifests through improper handling of compressed network messages within MongoDB's wire protocol implementation. When networkMessageCompressors is enabled, the database server processes compressed data streams that can be manipulated by attackers to trigger memory corruption vulnerabilities. This compression functionality, while intended to optimize network bandwidth usage, creates a pathway for attackers to craft malicious compressed payloads that can cause the MongoDB process to crash or behave unpredictably. The vulnerability operates at the protocol level, making it particularly dangerous as it can be exploited without requiring authentication or elevated privileges, directly impacting the server's memory management and process stability.
From an operational perspective, this vulnerability presents significant risks to MongoDB deployments, particularly in environments where attackers might have network access to database servers. The attack vectors include both denial of service conditions where the database process crashes or becomes unresponsive, and potential memory modification attacks that could lead to arbitrary code execution or data corruption. The impact extends beyond simple service disruption as the memory manipulation capabilities could potentially allow attackers to gain deeper access to the system or compromise the integrity of stored data. Organizations running affected MongoDB versions face increased risk of unauthorized access and system compromise, especially in cloud environments or multi-tenant deployments where network isolation may be incomplete.
The vulnerability aligns with CWE-129, which addresses improper handling of length parameters in memory operations, and represents a classic example of how compression algorithms can introduce security risks when not properly validated. According to ATT&CK framework, this vulnerability maps to T1499.004 for network denial of service and potentially T1059 for command execution if memory corruption leads to code execution. Organizations should immediately disable the networkMessageCompressors setting in their MongoDB configurations until a proper security update is applied, while also implementing network segmentation to limit exposure. The recommended mitigation includes upgrading to MongoDB 3.4.10 or later versions, where the vulnerability has been addressed through improved input validation and memory handling in the compression module. Security teams should also monitor for any attempts to enable this configuration setting in production environments, as it represents a clear indicator of potential compromise attempts.