Leostream Connection Broker 9.0.40.17 allows administrators to conduct directory traversal attacks by uploading z ZIP file that contains a symbolic link.
Conclusion & alert: CVE-2021-41551 is rated Low Risk (33.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.21%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-03-30 | 0.54% | 0.21% | -0.34% |
| 2 | 2025-03-29 | 0.21% | 0.54% | +0.34% |
| 3 | 2025-03-17 | — | 0.21% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.9 | 3.1 | MEDIUM |
|
1.2 | 3.6 | [email protected] |
| 4.0 | 2.0 | MEDIUM |
|
8.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| leostream | connection_broker | 9.0.40.17 | cpe:2.3:a:leostream:connection_broker:9.0.40.17:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://leostream.com/wp-content/uploads/2018/11/Leostream_release_notes.pdf | Release Notes Vendor Advisory |
| https://www.leostream.com/resource/leostream-connection-broker-9-0/ | Release Notes Vendor Advisory |