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CVE-2024-1709: ConnectWise ScreenConnect authentication bypass, mass-exploited

The short version: ConnectWise ScreenConnect has an authentication-bypass flaw (CVE-2024-1709) that lets an unauthenticated attacker reach the initial-setup wizard on an already-configured server and create a new administrator. Chained with a path-traversal bug (CVE-2024-1708), that means full takeover of a remote-access tool. It scores a perfect 10.0, it was mass-exploited within days of disclosure — including by ransomware crews — and it's in CISA's KEV catalog. If you self-host ScreenConnect, this is patch-and-verify. Steady hands — but move.

At a glance

FactDetail
Our severity takeModerate — in practice and on paper
CVSS v3.1 (NVD)10.0 — Critical · AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS99.96% · 99.98th percentile (2026-07-17)
In CISA KEV?Yes — remediation was due 2024-02-29
Known exploited?Yes — mass exploitation, including ransomware operators
Vulnerability typeCWE-288 authentication bypass using an alternate path → administrator creation
Requires authenticated session?No — pre-authentication
Chained withCVE-2024-1708 (path traversal) for code execution after takeover
AffectedScreenConnect 23.9.7 and all prior versions
Fixed inScreenConnect 23.9.8

What you need to know

ScreenConnect's setup wizard is meant to run once, when a server is first stood up. The bug lets an unauthenticated attacker reach that wizard on a fully configured server through an alternate path, and use it to create a brand-new administrator account.

This is about as bad as external exposure gets, and the target makes it worse:

  • It's a remote-access platform. Admin on ScreenConnect means the ability to push commands and software to every endpoint it manages — a direct route to fleet-wide compromise.
  • It's pre-authentication and trivially reachable. ScreenConnect servers are meant to be internet-facing so technicians can connect; no credential, no chain needed to get admin.
  • It was chained for full RCE. Paired with CVE-2024-1708 (path traversal), attackers moved from admin creation to code execution, and it saw immediate mass exploitation — including ransomware — which is why EPSS is essentially maxed.

How serious we see it

Moderate — the 10.0 is earned.

Unauthenticated administrator creation on an internet-facing remote-management server, confirmed mass-exploited, is the definition of top-of-queue. The bounded, reassuring part is that it's specific and fixed: it affects self-hosted ScreenConnect at or below 23.9.7, ConnectWise shipped 23.9.8, and exposure is quick to determine. The catch is the usual one — given how fast this was exploited, patched and clean are separate questions.

Recommendations

Straight from ConnectWise's advisory and CISA:

  1. Patch now. Upgrade self-hosted ScreenConnect to 23.9.8 or later. (ConnectWise-hosted cloud instances were remediated centrally.)
  2. Hunt for abuse. Check for newly created administrator accounts, unexpected extensions, and anomalous session activity.
  3. If compromised, respond fully. Remove rogue accounts, investigate managed endpoints for pushed payloads, and rotate credentials and secrets.
  4. Harden exposure. Limit who can reach the ScreenConnect server, and keep it on supported, patched builds.
  5. Confirm your exposure first. Verify whether you run a self-hosted ScreenConnect and which version.

How BreachRisk sees it

BreachRisk answers the first question — do we have an exposed, affected ScreenConnect? — from the outside in. Starting from little more than your domain, it discovers internet-facing ScreenConnect servers, fingerprints the version, and flags exposure tied to KEV-listed, actively exploited vulnerabilities like this one, surfaced at the top because it's in KEV. We identify and flag the affected version; we don't create accounts or exploit it. When an RMM zero-day breaks, the exposed server is already mapped, so you go straight to patch-and-verify.

References

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