ConnectWise ScreenConnect CVE-2024-57727 is a CVSS 7.5 path traversal disclosed on January 22, 2025, affecting self-hosted ScreenConnect versions before 25.2.4. It lets unauthenticated attackers read arbitrary files from the ScreenConnect server, including configuration files that contain database credentials and cryptographic keys. ScreenConnect is the backbone of many managed service providers, and this is the second major ScreenConnect vulnerability in 12 months following the CVE-2024-1709 authentication bypass. Remote access servers that hold delegated credentials to hundreds of customer environments are the worst possible place for arbitrary file read.
What exactly does CVE-2024-57727 let an attacker do?
CVE-2024-57727 lets an unauthenticated attacker read any file the ScreenConnect service account can access by submitting a crafted HTTP request with path-traversal sequences. The ScreenConnect web application exposes file-serving endpoints that fail to properly normalize path components before opening files. By encoding ../ sequences in specific parameter values, an attacker reaches outside the intended document root and into the server's filesystem.
The immediate value to an attacker is the ScreenConnect configuration directory, which contains:
User.xmlwith hashed administrator credentialsWeb.configwith database connection strings and encryption keys- Session database files holding active admin sessions
- License files and tenant metadata
Read access to these files is pre-authentication code execution by proxy: an attacker cracks or replays a session token, logs in as an admin, and then uses the normal ScreenConnect remote-access features to run code on every managed endpoint.
How does the exploitation flow actually work?
The exploitation flow works by sending a GET or POST request to a ScreenConnect file endpoint with path-traversal characters in a parameter the server treats as a filesystem path. The vulnerable endpoints are in the /App_Extensions/ and /Bin/ paths, where ScreenConnect serves files for extension loading and plugin distribution. The exact request pattern published by researchers in late January 2025 looks like:
GET /App_Extensions/%2E%2E%2F%2E%2E%2FUser.xml HTTP/1.1
Host: screenconnect.example.com
The server decodes the URL, fails to re-check path-normalization after decoding, and returns the contents of User.xml. The response includes admin bcrypt hashes. ScreenConnect's bcrypt work factor is reasonable, but rich target lists (MSPs, large enterprises) make GPU cracking worthwhile and several groups have pre-computed rainbow tables for common ScreenConnect password patterns.
Once the attacker has a valid admin credential, the path to full compromise is:
- Log in to the ScreenConnect web UI as admin
- Push an extension that runs an attacker-controlled command on every connected endpoint
- Deploy ransomware or infostealer across the entire fleet in parallel
This is the exact chain that Black Basta affiliates used against MSPs after the CVE-2024-1709 disclosure, and the 2025 incidents around CVE-2024-57727 followed the same playbook.
Which deployments are affected and how do you identify yours?
Deployments affected are self-hosted ScreenConnect installations running versions 25.2.3 and earlier. ConnectWise patched cloud-hosted instances centrally, so fully SaaS customers were closed quickly, but thousands of on-prem and MSP-hosted ScreenConnect servers required customer-driven upgrades. Identifying your exposure requires:
- Any Windows or Linux server running
ScreenConnect.Service - Any IIS site mapped to the ScreenConnect web application
- Any managed service provider in your supply chain that operates ScreenConnect
- Any customer-branded "remote support" portal that is actually a rebadged ScreenConnect
The last point is significant. ScreenConnect is white-labeled by thousands of MSPs under custom domain names, so the portal your vendor sends you to for support tickets might be ScreenConnect underneath. TPRM questionnaires should explicitly ask vendors whether their remote-support infrastructure is ScreenConnect, and if so which version.
Shodan and Censys snapshots in late January 2025 showed roughly 9,000 internet-facing self-hosted ScreenConnect servers that had not yet been updated to 25.2.4 two weeks after disclosure. The decay curve is slow because many of these are set up once and never maintained.
What detection signals reveal exploitation attempts?
Detection signals that reveal exploitation are URL patterns at the reverse proxy or WAF, file-read audit events, and post-exploitation admin logins. High-value signatures:
- Any request to
/App_Extensions/or/Bin/containing encoded path-traversal characters (%2E%2E,%2E%2E%2F,..%2F) - Any request for
User.xml,Web.config, or.configfiles outside normal administrative paths - Successful responses (HTTP 200) to requests containing traversal sequences
File-read audit signatures:
- Sysmon event 11 or FileSystemWatcher on the ScreenConnect config directory outside expected ScreenConnect service access patterns
- Changes to
User.xmlor addition of unexpected admin accounts - New extension packages uploaded through the web UI
Post-exploitation signatures:
- ScreenConnect agent processes on endpoints spawning unusual children (
cmd.exe,powershell.exe,rundll32.exewith suspicious arguments) - Mass deployment of the same extension or script across many endpoints in a short window
- Admin login from a new IP or an IP without prior admin activity
The post-exploitation signals are the ones that caught MSP-level incidents after CVE-2024-1709, and the same detections apply here because the post-authentication attack path is identical.
What does the full remediation plan look like for self-hosted and MSP cases?
The full remediation plan combines patching, credential rotation, and hardening. Patch to ScreenConnect 25.2.4 or later. For self-hosted instances that were exposed before patching, assume that admin credentials and encryption keys were stolen and rotate:
- All ScreenConnect admin passwords
- The ScreenConnect database connection string (if SQL server-backed)
- The server encryption key, which invalidates existing session tokens and forces re-authentication
- Any SSO integration secrets (SAML, OIDC client secrets)
For endpoints that were managed by a potentially compromised ScreenConnect instance, the containment scope depends on whether you can audit every command executed by the ScreenConnect agent during the exposure window. ConnectWise logs are helpful but not complete; incident response should assume any endpoint could have received arbitrary commands and plan for endpoint rebuilds if you cannot prove otherwise.
Hardening beyond the immediate patch:
- Move self-hosted ScreenConnect to cloud-hosted if operational requirements allow it
- Restrict ScreenConnect web UI access to a VPN or IP allowlist
- Enable MFA on all admin accounts
- Configure strict web-server log retention for incident response
MSP customers should ask their provider for evidence of the specific patched version, timing of credential rotation, and audit logs for the exposure window. "We are on the latest version" is not an acceptable answer without version numbers and timestamps.
How does this fit into the broader remote-access supply chain risk picture?
Remote access tools like ScreenConnect, TeamViewer, AnyDesk, and Atera are concentrated choke points in the IT supply chain. A compromise of one of these platforms reaches every endpoint it manages, which in the MSP case can mean hundreds of customer environments hit simultaneously. The pattern of CVE-2024-1709 followed by CVE-2024-57727 within 12 months shows that the attack surface is under active research by both legitimate security teams and threat actors, and additional vulnerabilities are predictable.
Supply chain programs need to treat RMM (remote monitoring and management) platforms as Tier 0 critical infrastructure alongside identity providers and certificate authorities. Vendor selection should weigh architecture (cloud-first versus self-hosted), patch velocity, and transparency of incident disclosure. ConnectWise's disclosure on CVE-2024-57727 was timely but the market still contains many small RMM vendors with weaker practices.
How Safeguard.sh Helps
Safeguard.sh identifies every ScreenConnect instance in your estate, including white-labeled MSP deployments, through 100-level binary-aware dependency scanning across your own environment and your third-party vendor surface. Reachability analysis removes 60 to 80 percent of noise by flagging which instances are actually exposed to untrusted networks versus those behind VPN or allowlists. Griffin AI autonomously proposes patch orchestration, credential rotation runbooks, and WAF rules tailored to your ingress topology, while container self-healing rebuilds affected images. SBOM generation and ingest unify build-time and runtime views across ScreenConnect and related RMM platforms, and the TPRM workflow surfaces MSPs and vendors running unpatched ScreenConnect before they become incident vectors.