Improper Restriction of Operations within the Bounds of a Memory Buffer
An issue was discovered in NVR WebViewer on Hanwah Techwin SRN-472s 1.07_190502 devices, and other SRN-x devices before 2019-05-03. A system crash and reboot can be achieved by submitting a long username in excess of 117 characters. The username triggers a buffer overflow in the main process controlling operation of the DVR system, rendering services unavailable during the reboot operation. A repeated attack affects availability as long as the attacker has network access to the device.
CWE-119 - Buffer Overflow
Buffer overflow attacks involve data transit and operations exceeding the restricted memory buffer, thereby corrupting or overwriting data in adjacent memory locations. Such overflow allows the attacker to run arbitrary code or manipulate the existing code to cause privilege escalation, data breach, denial of service, system crash and even complete system compromise. Given that languages such as C and C++ lack default safeguards against overwriting or accessing data in their memory, applications utilizing these languages are most susceptible to buffer overflows attacks.