CVE-2019-25572
Denial of Service via Buffer Overflow in NordVPN
Publication date: 2026-03-21
Last updated on: 2026-04-15
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| nordvpn | nordvpn | to 6.19.6 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-1260 | The product allows address regions to overlap, which can result in the bypassing of intended memory protection. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2019-25572 is a denial of service vulnerability in NordVPN version 6.19.6 and earlier. It occurs because the application improperly handles input in the email field during login.
An attacker can submit an excessively long string—specifically, a buffer of 100,000 characters—into the email input field. This causes a buffer overflow that crashes the NordVPN client application.
The attack is local, meaning the attacker must have access to the system running NordVPN. No special privileges or user interaction are required beyond pasting the large input into the email field.
How can this vulnerability impact me? :
This vulnerability can cause the NordVPN client application to crash, resulting in a denial of service.
Because the application crashes, legitimate users may be unable to use NordVPN until the application is restarted or the issue is resolved.
The impact is on availability, meaning the VPN service becomes temporarily unavailable, which could disrupt secure network connections.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': 'This vulnerability can be detected by attempting to reproduce the denial of service condition on the affected NordVPN client version 6.19.6 by submitting an excessively long string in the email input field during login.'}, {'type': 'paragraph', 'content': 'A proof-of-concept method involves creating a buffer of 100,000 characters and pasting it into the email field of the NordVPN login interface to observe if the application crashes.'}, {'type': 'list_item', 'content': "Run a Python script to generate a file (e.g., PoC.txt) containing 100,000 'A' characters."}, {'type': 'list_item', 'content': 'Copy the contents of this file to the clipboard.'}, {'type': 'list_item', 'content': 'Open the NordVPN application and paste the large buffer into the email field.'}, {'type': 'list_item', 'content': 'Enter any password and attempt to sign in.'}, {'type': 'paragraph', 'content': 'If the application crashes, the vulnerability is present.'}] [1]
What immediate steps should I take to mitigate this vulnerability?
I don't know