CVE-2019-25353: Foscam Video Management System DoS Flaw

CVE-2019-25353 Overview

CVE-2019-25353 is a buffer overflow vulnerability in Foscam Video Management System version 1.1.4.9 that allows attackers to trigger a denial of service condition. The vulnerability exists in the username input field during device login, where an attacker can submit a specially crafted 520-byte buffer of repeated characters to crash the application. This buffer overflow vulnerability (CWE-120) occurs due to improper bounds checking on user-supplied input in the authentication mechanism.

Critical Impact

Attackers can crash the Foscam Video Management System application by exploiting the username field buffer overflow, disrupting video surveillance monitoring capabilities.

Affected Products

• Foscam Video Management System version 1.1.4.9

Discovery Timeline

• 2026-02-18 - CVE CVE-2019-25353 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2019-25353

Vulnerability Analysis

This vulnerability stems from a classic buffer overflow condition (CWE-120: Buffer Copy without Checking Size of Input) in the Foscam Video Management System's authentication handler. The application fails to properly validate the length of user-supplied input in the username field before copying it to a fixed-size buffer. When an attacker provides input exceeding the expected buffer size, memory corruption occurs, leading to application instability and ultimately a crash.

The local attack vector requires user interaction, meaning an attacker would need to either have local access to a system running the vulnerable software or convince a user to interact with a malicious login attempt. The exploitation results in availability impact through application termination, disrupting video management and surveillance monitoring capabilities.

Root Cause

The root cause is improper input validation in the username field handling routine. The application allocates a fixed-size buffer for storing username input but does not enforce length restrictions before copying user-supplied data. When input exceeding 520 bytes is provided, the buffer boundary is violated, causing memory corruption that triggers an application crash. This classic buffer overflow pattern indicates a lack of secure coding practices in input handling routines.

Attack Vector

The attack is executed locally and requires user interaction with the application. An attacker constructs a malicious payload consisting of a 520-byte buffer filled with repeated characters (such as 'A' characters) and submits this as the username during the device login process. The oversized input overwrites adjacent memory, corrupting critical data structures and causing the Video Management System to crash.

According to the Exploit-DB #47671 entry, the exploit involves overwriting the username with this specific buffer size to reliably trigger the denial of service condition. The attack does not require authentication, making it accessible to any user who can interact with the login interface.

Detection Methods for CVE-2019-25353

Indicators of Compromise

• Unexpected application crashes of Foscam Video Management System during login attempts
• Log entries showing abnormally long username values in authentication requests
• Memory access violations or segmentation faults in application error logs
• Repeated application restarts without user intervention

Detection Strategies

• Monitor application event logs for crash events associated with the Video Management System executable
• Implement input length monitoring on authentication endpoints to detect oversized username submissions
• Deploy endpoint detection rules that alert on buffer overflow patterns targeting surveillance software
• Use application crash analysis tools to identify crashes caused by memory corruption in authentication modules

Monitoring Recommendations

• Enable verbose logging for the Foscam Video Management System authentication module
• Configure system monitoring to track application stability and restart frequency
• Implement network monitoring for unusual patterns in authentication traffic to video management systems
• Set up alerting for application crashes during business hours when surveillance is critical

How to Mitigate CVE-2019-25353

Immediate Actions Required

• Restrict local access to systems running Foscam Video Management System version 1.1.4.9
• Implement network segmentation to isolate video management systems from untrusted users
• Monitor for application crashes and investigate any denial of service incidents
• Contact Foscam support for information regarding patched versions or updated software

Patch Information

No vendor patch information is currently available in the CVE data. Organizations should monitor the Foscam Official Website for security updates and newer software versions that address this vulnerability. Additionally, review the VulnCheck Advisory on Foscam DoS for the latest remediation guidance.

Workarounds

• Implement input validation at the network perimeter to reject oversized authentication requests before they reach the application
• Deploy application-level firewall rules to limit username field input length
• Restrict physical and logical access to systems running the vulnerable software
• Consider deploying alternative video management software until a patch is available
• Enable application restart monitoring to automatically recover from crash events

Organizations should prioritize upgrading to a patched version when available, as workarounds only provide temporary protection against this buffer overflow vulnerability.