Vulnerability · CVE-2021-4463
Longjing Technology BEMS API versions up to and including 1.21 contains an unauthenticated arbitrary file download vulnerability in the 'downloads' endpoint.
Published Nov 12, 2025 · catalog updated May 14, 2026 · Shenzhen Longjing Technology Co. Ltd. BEMS API
Last checked Nov 3, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2021-4463. EPSS is 1.54%. Act only if a listed version of Shenzhen Longjing Technology Co. Ltd. BEMS API is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High8.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 1.54%
- Remediation
- Advisory link
- Affected products
- vendor Shenzhen Longjing Technology Co. Ltd. BEMS API 0 ≤1.21
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Shenzhen Longjing Technology Co. Ltd. BEMS API 0 ≤1.210 ≤1.21
How to fix CVE-2021-4463
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
Seen in 0 ≤1.21
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2021-4463. EPSS is 1.54%. Act only if a listed version of Shenzhen Longjing Technology Co. Ltd. BEMS API is installed.
Which versions are affected?
Compare what you have installed with Shenzhen Longjing Technology Co. Ltd. BEMS API 0 ≤1.21 0 ≤1.21. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 1.54%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Nov 12, 2025 · EUVD
Detected
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.
May 14, 2026 · EUVD
Updated
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.
Sources
- CVE.orgVulnerability recordCVE-2021-4463
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-4463
30-day exploitation probability 1.54%
first.org - EUVDVulnerability recordEUVD-2021-34715
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 f
euvd.enisa.europa.eu - Packet Storm SecurityCited referencehttps://packetstormsecurity.com/files/163702
Packet Storm link already published on the finding.
packetstormsecurity.com
References
Freshness
Last verified in this catalog Nov 2, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- Packet Storm SecurityNov 3, 2026
- FIRST EPSSNov 2, 2026
- CVE.orgOct 24, 2026
- EUVDOct 23, 2026