CVE-2016-8919 in WebSphere Application Server
Summary
by MITRE
IBM WebSphere Application Server may be vulnerable to a denial of service, caused by allowing serialized objects from untrusted sources to run and cause the consumption of resources.
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Analysis
by VulDB Data Team • 09/17/2024
IBM WebSphere Application Server vulnerability CVE-2016-8919 represents a critical security flaw that enables unauthorized denial of service attacks through insecure deserialization of untrusted data. This vulnerability resides in the application server's handling of serialized objects, which are binary representations of objects that can be transmitted across networks or stored in files. When the server accepts serialized data from untrusted sources without proper validation, it becomes susceptible to malicious exploitation that can lead to resource exhaustion and system instability.
The technical implementation of this vulnerability stems from the server's failure to properly validate and sanitize serialized object inputs. When an attacker sends specially crafted serialized objects to the WebSphere server, the application attempts to deserialize these objects without adequate security checks. This process can trigger unexpected behavior including infinite loops, stack overflows, or excessive memory allocation that consumes system resources. The flaw is categorized under CWE-502 as Deserialization of Untrusted Data, which is a well-documented weakness in software security that has been exploited in numerous high-profile attacks. The vulnerability allows attackers to manipulate the deserialization process in ways that can cause the application server to consume excessive CPU cycles or memory resources, ultimately leading to denial of service conditions that prevent legitimate users from accessing services.
The operational impact of CVE-2016-8919 extends beyond simple service disruption to potentially compromise the entire application server infrastructure. Attackers can leverage this vulnerability to consume system resources continuously, causing the server to become unresponsive or crash entirely. This can result in significant downtime for organizations relying on WebSphere applications, potentially affecting thousands of users and causing substantial financial losses. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for automated attack tools. According to ATT&CK framework technique T1499.004, this vulnerability enables resource exhaustion attacks that can be classified as a form of denial of service, where the attacker consumes system resources to prevent legitimate use of services.
Organizations should implement multiple layers of defense to mitigate this vulnerability effectively. The primary mitigation involves configuring the WebSphere server to disable deserialization of untrusted data or to implement strict validation mechanisms for all serialized objects. Security administrators should also establish network-level controls that restrict access to the application server's deserialization endpoints and implement monitoring solutions that can detect unusual resource consumption patterns. IBM has released patches and fixes for this vulnerability that should be applied immediately to all affected systems. Additionally, organizations should conduct regular security assessments to identify potential entry points for similar vulnerabilities and implement secure coding practices that prevent insecure deserialization in custom applications. The vulnerability demonstrates the critical importance of input validation and the principle of least privilege in application security, as it highlights how seemingly simple functionality can become a gateway for sophisticated attacks when not properly secured.