CVE-2015-1956 in MQ Light
Summary
by MITRE
IBM MQ Light before 1.0.0.2 allows remote attackers to cause a denial of service (disk consumption) via a crafted byte sequence in authentication data, a different vulnerability than CVE-2015-1958 and CVE-2015-1987.
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Analysis
by VulDB Data Team • 09/04/2017
IBM MQ Light represents a messaging system designed for lightweight communication between applications, particularly in cloud and mobile environments. The vulnerability CVE-2015-1956 specifically targets the authentication mechanism within this system, creating a path for remote attackers to exploit a flaw in how the system processes authentication data. This vulnerability operates through a crafted byte sequence that when injected into the authentication process causes the system to consume excessive disk resources, ultimately leading to a denial of service condition. The flaw is distinct from other related vulnerabilities in the same timeframe, indicating a unique code path or implementation issue within the authentication handling component.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted authentication data containing malicious byte sequences that trigger improper memory or disk handling within the MQ Light system. This causes the system to allocate excessive storage resources for processing the malformed authentication data, leading to rapid disk space exhaustion. The vulnerability specifically affects IBM MQ Light versions prior to 1.0.0.2, indicating that this was a targeted issue within the authentication subsystem that was addressed through version updates. The attack vector is remote, meaning that an attacker does not require physical access to the system but can exploit this through network communication.
The operational impact of CVE-2015-1956 extends beyond simple service disruption to potentially compromise system availability and stability. When disk consumption occurs at an accelerated rate due to this vulnerability, it can lead to complete system outages where legitimate services cannot operate due to insufficient storage space. Organizations using IBM MQ Light for critical messaging infrastructure may experience cascading failures as the system becomes unresponsive, affecting application connectivity and data flow across their networked environments. This type of denial of service attack directly violates the availability principles of the CIA triad and can have significant business continuity implications.
Security mitigations for CVE-2015-1956 primarily involve upgrading to IBM MQ Light version 1.0.0.2 or later, which contains the necessary patches to address the authentication data handling flaw. Organizations should implement network monitoring to detect unusual disk consumption patterns that might indicate exploitation attempts, and establish baseline performance metrics to quickly identify when systems begin consuming storage resources abnormally. Additionally, access controls should be strengthened to limit the attack surface, and security audits should verify that authentication mechanisms are properly configured to reject malformed data sequences. This vulnerability aligns with CWE-129, which addresses issues related to improper validation of input data, and represents a classic example of how malformed input processing can lead to resource exhaustion attacks. The ATT&CK framework categorizes this under privilege escalation and denial of service techniques, as attackers can leverage the vulnerability to gain control over system resources and disrupt service availability.