CVE-2025-29897: Buffer Copy Vulnerability in Qsync Central <5.0.0.4
CVE-2025-29897 Published on October 15, 2026
Stack-based Buffer Overflow in qsyncsrv.cgi
A buffer copy without checking size of input vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to modify memory or crash processes.
We have already fixed the vulnerability in the following version:
Qsync Central 5.0.0.4 and later
Vulnerability Analysis
CVE-2025-29897 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Types
What is a Classic Buffer Overflow Vulnerability?
The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. A buffer overflow condition exists when a program attempts to put more data in a buffer than it can hold, or when a program attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the program copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
CVE-2025-29897 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
What is a Stack Overflow Vulnerability?
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CVE-2025-29897 has been classified to as a Stack Overflow vulnerability or weakness.
Products Associated with CVE-2025-29897
Want to know whenever a new CVE is published for QNAP Qsync Central? stack.watch will email you.
Affected Versions
QNAP Systems Inc. Qsync Central:- Version 5.0.x and below 5.0.0.4 is affected.