Read the docs
TI-2021-15837 Aliases CVE-2021-38157GHSA-q29w-c798-qpqq

LeoStream Connection Broker 9.x before 9.0.34.3 allows Unauthenticated Reflected XSS via…

Priority MEDIUM 60CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-79.

Summary

LeoStream Connection Broker 9.x before 9.0.34.3 allows Unauthenticated Reflected XSS via the /index.pl user parameter. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01119 66th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:leostream:connection_broker:*:*:*:*:*:*:*:*9.0.3 to before 9.0.34.3VulnerableLeostream
  • cpe:2.3:a:leostream:connection_broker:*:*:*:*:*:*:*:* Versions 9.0.3 to before 9.0.34.3 Vulnerable ·Leostream

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-38157
  2. 2026-10-03 Alias added: GHSA-q29w-c798-qpqq

References

Exploit 1

Advisory 3

  • TI-2020-16205 Leostream Connection Broker 8.2.x is affected by stored XSS. CVSS 3.1CRITICAL 9.6
  • TI-2018-13327 The Leostream Agent before Build 7.0.1.0 when used with Leostream Connection Broker… CVSS 3.0HIGH 7.5
  • TI-2021-18287 Leostream Connection Broker 9.0.40.17 allows administrator to upload and execute Perl code. CVSS 3.1HIGH 7.2
  • TI-2021-18288 Leostream Connection Broker 9.0.40.17 allows administrators to conduct directory… CVSS 3.1MEDIUM 4.9

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences