An issue was discovered in ExpressVPN on Windows.

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• expressvpn expressvpnall versions

Other highest-scoring records for the same primary product.

• CVE-2020-29238An integer buffer overflow in the Nginx webserver of ExpressVPN Router version 1 allows remote attackers to obtain sensitive information whe
  35Monitor
• CVE-2024-25728ExpressVPN before 12.73.0 on Windows, when split tunneling is used, sends DNS requests according to the Windows configuration (e.g., sends t
  30Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1const file = path.join(ROOT, req.query.name);2res.sendFile(file);

1const file = path.resolve(ROOT, req.query.name);2if (!file.startsWith(ROOT + path.sep)) {3  return res.sendStatus(400);4}5res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.