CVE-2025-29895 in Qsync Central
Summary
by MITRE • 10/15/2026
A NULL pointer dereference vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack.
We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 and later
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Analysis
by VulDB Data Team • 10/15/2026
The reported issue involves a NULL pointer dereference within the Qsync Central application, which represents a significant stability risk for systems relying on this synchronization service. A NULL pointer dereception occurs when software attempts to access memory at address zero or another invalid location that is reserved by the operating system and not allocated for general use. In the context of network-facing services like Qsync Central, such vulnerabilities are particularly dangerous because they can be triggered remotely if an attacker has valid authentication credentials. While the requirement for a user account limits the attack surface compared to unauthenticated exploits, it does not eliminate the threat entirely, as compromised or stolen legitimate credentials remain a common vector in enterprise environments.
From a technical perspective, this flaw indicates that the application fails to adequately validate input data before passing pointers to underlying functions or memory operations. When specific malformed requests are processed by Qsync Central, the internal logic likely assumes a pointer is valid and points to allocated memory. However, due to missing validation checks, the pointer remains NULL. The subsequent attempt to read from or write to this null address causes the operating system to raise an exception, typically resulting in the immediate termination of the affected process thread or service instance. This behavior aligns with Common Weakness Enumeration standard CWE-476, which defines a NULL Pointer Dereference as a condition where software performs a dereference of a pointer that evaluates to NULL, leading to unexpected application exit and potential denial of service conditions.
The operational impact of this vulnerability is primarily centered on availability rather than confidentiality or integrity. An authenticated attacker can exploit the flaw to crash the Qsync Central service repeatedly, effectively launching a denial-of-service attack against the synchronization infrastructure. This disruption prevents legitimate users from syncing files, accessing shared resources, or performing routine administrative tasks associated with the platform. In an enterprise setting where continuous data availability is critical, such instability can lead to significant productivity losses and operational downtime. The attacker does not gain elevated privileges or execute arbitrary code through this specific flaw; instead, they leverage it as a tool for disruption, which corresponds to the Initial Access and Impact tactics within the MITRE ATT&CK framework, specifically relating to service stoppage via resource exhaustion or application crash techniques.
To mitigate this risk, organizations must ensure that all instances of Qsync Central are updated to version 5.0.0.4 or later, where the vendor has implemented fixes for the underlying code defect. Beyond patching, it is advisable to enforce strict access controls and multi-factor authentication to reduce the likelihood of credential compromise, thereby limiting the pool of potential attackers who could trigger this vulnerability. Additionally, deploying network-level monitoring solutions can help detect anomalous patterns of requests that may indicate exploitation attempts, allowing security teams to respond proactively before service disruption occurs. Regular auditing of application logs for crash reports or error codes associated with memory access violations will also aid in identifying any residual instances where the patch might have been missed or misconfigured.