CVE-2021-4463

Longjing Technology BEMS API <= 1.21 Remote Arbitrary File Download

8.7 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

1.54%Up 1.5 points since Nov 13, 2025

What each source reports

CVE List Score used 8.7

Longjing Technology BEMS API <= 1.21 Remote Arbitrary File Download

Record: CVE-2021-4463
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-552, CWE-22
Updated: 2026-11-02

EUVDEUVD-2021-34715 8.7

Record: EUVD-2021-34715
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-4m64-g8r6-3ghw 8.7

Longjing Technology BEMS API versions up to and including 1.21 contains an unauthenticated...

Record: GHSA-4m64-g8r6-3ghw
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-22
Updated: 2026-11-02

NVD 8.7

Record: CVE-2021-4463
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-22, CWE-552
Updated: 2026-11-02

Affected products

shenzhen longjing technology co. ltd. bems api

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Nuclei	Longjing Technology BEMS API 1.21 - Unauthenticated Arbitrary File Download

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, Nuclei, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-4463 is a high vulnerability (CVSS 8.7) in Shenzhen Longjing Technology Co. Ltd. Bems Api, published November 12, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.54%, the 75th percentile. No source names a fixed version.