CVE-2021-4463

Longjing Technology BEMS API <= 1.21 Remote Arbitrary File Download

State: Published
Severity: 8.7 High
Published: Nov 12, 2025
Updated: May 14, 2026
Reserved: Nov 12, 2025

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.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N	VulnCheck

Weaknesses

CWE-552 Files or Directories Accessible to External Parties
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

Product	Versions
BEMS APIShenzhen Longjing Technology Co. Ltd.	1.21 and earlierAffected

References

https://www.zeroscience.mk/en/vulnerabilities/ZSL-2021-5657.phptechnical-descriptionexploit
https://www.exploit-db.com/exploits/50163exploit
https://packetstormsecurity.com/files/163702exploit
https://cxsecurity.com/issue/WLB-2021070173exploit
https://exchange.xforce.ibmcloud.com/vulnerabilities/206477vdb-entry
https://web.archive.org/web/20220527162453/http://www.ljkj2012.com/product
https://www.vulncheck.com/advisories/longjing-technology-bems-api-remote-arbitrary-file-downloadthird-party-advisory

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