CVE-2023-32611 in glib
Summary
by MITRE • 09/14/2023
A flaw was found in GLib. GVariant deserialization is vulnerable to a slowdown issue where a crafted GVariant can cause excessive processing, leading to denial of service.
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Analysis
by VulDB Data Team • 06/23/2026
The vulnerability resides within the glib library's GVariant deserialization functionality, which serves as a core component for handling structured data in various applications and systems. This flaw represents a denial of service condition that can be triggered through carefully crafted GVariant data structures. The issue stems from insufficient input validation and processing controls during the deserialization phase, where maliciously constructed variant data can cause the system to enter into excessive computational loops or resource consumption patterns. When an application processes such malformed GVariant data, the deserializer fails to properly limit its processing time or memory usage, leading to significant performance degradation or complete system unresponsiveness.
The technical implementation of this vulnerability leverages the inherent design characteristics of GVariant's parsing mechanisms within GLib. During deserialization, the parser encounters specific data patterns that cause it to recursively process nested structures or iterate through data in ways that scale exponentially with input complexity. This behavior creates a scenario where an attacker can craft input that forces the system to perform excessive computation cycles, effectively consuming available CPU resources and potentially causing memory exhaustion. The vulnerability is particularly dangerous because GVariant is widely used across various software components including desktop environments, network services, and system utilities, making numerous applications susceptible to this attack vector.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader system stability concerns. When exploited, the slowdown issue can affect not only individual applications but entire system processes that rely on GLib's variant handling capabilities. Attackers can leverage this weakness in environments where applications process untrusted data from external sources such as network communications, file parsing, or user input validation. The vulnerability is especially concerning in server environments and network services where continuous availability is critical, as it can be used to perform sustained denial of service attacks that are difficult to distinguish from legitimate system performance issues.
Mitigation strategies for this vulnerability should focus on implementing proper input sanitization and resource limiting measures within applications that utilize GLib's GVariant functionality. System administrators should ensure that all affected applications are updated to versions containing the patched GLib implementation, which typically includes enhanced bounds checking and processing time limitations. Organizations should also consider implementing monitoring and alerting mechanisms to detect unusual processing patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-770, which addresses allocation of resources without limits or appropriate checks, and can be mapped to ATT&CK technique T1499.004 for denial of service through resource exhaustion. Additionally, defensive programming practices such as implementing timeout mechanisms and input length restrictions should be enforced at multiple layers of application architecture to provide defense in depth against similar vulnerabilities.