CVE-2021-4463 Longjing Technology BEMS API <= 1.21 Remote Arbitrary File Download
Unauthenticated attackers can exploit path traversal in the downloads endpoint to read sensitive files from the server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-4463?
CVE-2021-4463 is a high-severity path traversal vulnerability in Shenzhen Longjing Technology Co. Ltd. BEMS API, published on 12 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Longjing Technology BEMS API versions up to and including 1.21 contains an unauthenticated arbitrary file download vulnerability in the 'downloads' endpoint. The 'fileName' parameter is not properly sanitized, allowing attackers to craft traversal sequences and access sensitive files outside the intended directory.
Which versions are affected by CVE-2021-4463?
How do I fix CVE-2021-4463?
No fix has been published for CVE-2021-4463 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2021-4463 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-4463 exists.
Public exploit code: 1 Nuclei template.
Sources
Also known as GHSA-4m64-g8r6-3ghw.