Over 1,500 Jenkins Controllers Exposed Online, Raising Serious Security Concerns

A ZoomEye scan has identified at least 1,537 internet-reachable Jenkins automation server instances, highlighting a persistent and large-scale attack surface. Jenkins is frequently deployed by build teams without security oversight, often on public-facing virtual machines for ease of access by external agents and webhooks. The plugin-heavy architecture further complicates patching, as administrators must track vulnerabilities across both the core product and numerous extensions. A notable example is CVE-2024-23897, a flaw allowing unauthenticated attackers to read sensitive files — including credentials — from exposed controllers via the CLI. Security experts recommend placing Jenkins behind a VPN or identity-aware proxy, enforcing strict patch management, rotating stored credentials, and treating any internet-facing controller as a priority security finding.