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CVE-2021-30119: Kaseya VSA Cross-site Scripting Vulnerability Exploitation (CVE-2021-30119)

The short version: Affected Kaseya VSA servers are vulnerable to an authenticated reflective XSS in the HelpDeskTab/rcResults.asp endpoint. The parameter result of /HelpDeskTab/rcResults.asp is insecurely returned in the requested web page and can be used to perform a Cross Site Scripting attack. BreachRisk discovers exposed instances from your attack surface and flags this finding so you can prioritize by real-world breach risk.

At a glance

FactDetail
Our severity takeModerate — BreachRisk score 4.0 (impact 2, likelihood 3)
CVSS v3.1 (NVD)Unknown at time of writing
In CISA KEV?Unknown at time of writing — check the KEV catalog
Known exploited?Unknown at time of writing
Requires authenticated session?Unknown at time of writing
CVECVE-2021-30119

What you need to know

Exposed Kaseya VSA Server appears vulnerable to exploitation of cross-site scripting (xss) vulnerability (CVE-2021-30119).

  • How they find it — internet-facing exposure of the affected product is discoverable by routine scanning.
  • How they use it — attackers exploit the vulnerability against reachable instances.
  • What it leads to — compromise of the affected service and, depending on placement, a foothold for further movement.

How serious we see it

Moderate — based on BreachRisk impact and likelihood scoring for this threat definition (score 4.0/9). Treat internet-facing instances as priority; confirm exposure and patch status before assuming you're clear.

Recommendations

  1. Apply security update to exposed Kaseya VSA Server.
  2. Restrict access to affected Kaseya instances to only trusted IP addresses.

How BreachRisk sees it

BreachRisk discovers internet-facing assets tied to this threat, fingerprints the product where possible, and flags exposure for CVE-2021-30119. Where authorized, it can go beyond detection with a bounded, non-disruptive check rather than leaving you with a maybe. Continuous outside-in coverage means the exposed service is already on your radar ranked by how it actually gets used against you.

References

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