CVE-2023-29499 in glib
Summary
by MITRE • 09/14/2023
A flaw was found in GLib. GVariant deserialization fails to validate that the input conforms to the expected format, leading to denial of service.
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Analysis
by VulDB Data Team • 05/25/2026
The vulnerability resides within the GLib library's GVariant deserialization functionality, which serves as a fundamental component for handling structured data in various applications and systems. This flaw represents a critical validation failure that allows malformed input to bypass expected format checks during the deserialization process. The issue manifests when GVariant attempts to parse data structures without proper validation of the input format, creating a potential vector for denial of service attacks. According to CWE-20, this vulnerability stems from inadequate input validation practices that permit unexpected data patterns to be processed without sufficient sanitization measures. The flaw impacts systems that rely on GLib's GVariant functionality for data handling, particularly those using the library for inter-process communication, configuration management, or data serialization tasks.
The technical implementation of this vulnerability exploits the absence of comprehensive format validation during GVariant deserialization operations. When malformed or unexpected data structures are fed into the deserialization routine, the system fails to properly validate the input against the expected GVariant format specifications. This validation gap allows attackers to craft specially crafted inputs that can cause the deserialization process to enter an invalid state or consume excessive computational resources. The vulnerability does not appear to enable arbitrary code execution directly but creates conditions that can lead to resource exhaustion or application crashes. From an ATT&CK perspective, this weakness maps to T1499.004 which covers network disruption and service availability attacks through resource exhaustion techniques. The flaw particularly affects systems where GLib's GVariant is used in network services or applications processing untrusted data from external sources.
The operational impact of this vulnerability extends across numerous software ecosystems that depend on GLib, including desktop environments, mobile applications, and server-side systems. Applications using GVariant for parsing configuration files, handling IPC messages, or processing user-provided data become susceptible to denial of service conditions when exposed to malformed input. Attackers can exploit this weakness by providing crafted data that causes the deserialization process to consume excessive memory or processing cycles, ultimately leading to system instability or complete service unavailability. The vulnerability affects both client-side applications and server implementations, making it particularly dangerous in environments where GLib is extensively used for data handling operations. Organizations running systems with vulnerable GLib versions may experience unexpected application crashes, performance degradation, or complete service outages, especially in high-traffic scenarios where the deserialization process is frequently invoked.
Mitigation strategies for this vulnerability should focus on immediate patch application from GLib maintainers, as the most effective solution addresses the root cause through proper input validation. System administrators should prioritize updating GLib components across all affected systems, particularly those handling untrusted input data. Additional defensive measures include implementing input sanitization layers that validate data formats before passing them to GVariant deserialization routines, deploying monitoring systems to detect unusual resource consumption patterns, and establishing network segmentation to limit exposure of vulnerable services. Organizations should also consider implementing application-level firewalls or API gateways that can filter malformed input before it reaches the vulnerable deserialization functions. From a compliance standpoint, this vulnerability aligns with security standards requiring proper input validation and resource management practices, emphasizing the need for robust defensive programming techniques to prevent similar issues in other components of the software stack.