CVE-2025-43015 Overview
CVE-2025-43015 affects JetBrains RubyMine versions before 2025.1. The remote interpreter feature overwrote user-defined port bindings and listened on all network interfaces instead of localhost. This exposure allows unauthenticated network attackers to interact with the interpreter service from remote hosts. The flaw maps to [CWE-1188] Insecure Default Initialization of Resource. JetBrains addressed the issue in RubyMine 2025.1 as documented in the JetBrains Security Issues Fixed advisory. No public proof-of-concept exploit or in-the-wild exploitation has been reported.
Critical Impact
Remote attackers on adjacent or reachable networks can access the RubyMine remote interpreter service, potentially reading development context and interfering with interpreter operations.
Affected Products
- JetBrains RubyMine versions prior to 2025.1
- Developer workstations running affected RubyMine builds with remote interpreter enabled
- Environments where RubyMine binds interpreter services to network-reachable interfaces
Discovery Timeline
- 2025-04-17 - CVE-2025-43015 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-43015
Vulnerability Analysis
The vulnerability stems from insecure default network binding in the RubyMine remote interpreter component. When a developer configured a remote interpreter, RubyMine overwrote the intended port binding and caused the service to listen on 0.0.0.0 instead of a loopback address. This exposed the interpreter's port to every network interface reachable from the host. Attackers on the same network segment can connect to the exposed service without authentication. The confidentiality and integrity impact is limited but non-zero, as reflected in the vulnerability metrics.
Root Cause
The root cause is classified as [CWE-1188], Insecure Default Initialization of Resource. RubyMine's remote interpreter initialization logic did not respect the user-supplied interface binding and defaulted to all interfaces. This behavior violates the principle of least exposure for local development tooling, which should bind to 127.0.0.1 unless explicitly configured otherwise.
Attack Vector
An attacker with network reachability to a developer workstation running vulnerable RubyMine can connect directly to the interpreter port. No credentials or user interaction are required. The attacker can query the interpreter service, potentially observe development artifacts exposed through the channel, and inject requests that the interpreter would treat as originating from a local IDE session. Exploitation requires the developer to have an active remote interpreter session running.
No verified public exploit code is available. See the JetBrains Security Issues Fixed advisory for vendor details.
Detection Methods for CVE-2025-43015
Indicators of Compromise
- Unexpected inbound TCP connections to developer workstations targeting ephemeral high ports opened by rubymine or Ruby interpreter processes
- RubyMine processes bound to 0.0.0.0 rather than 127.0.0.1 when inspected via netstat or ss
- Firewall or NetFlow logs showing external hosts communicating with developer workstations on interpreter ports
Detection Strategies
- Enumerate installed RubyMine versions across developer endpoints and flag any build prior to 2025.1
- Query endpoint telemetry for listening sockets owned by RubyMine or child Ruby processes bound to non-loopback interfaces
- Correlate developer workstation network flows to identify unexpected remote connections to IDE-owned ports
Monitoring Recommendations
- Alert on any process associated with RubyMine that opens a listening socket outside 127.0.0.1 or ::1
- Monitor egress and lateral network traffic from developer subnets for connections to IDE-related ports
- Baseline normal remote interpreter usage and alert on deviations in source IP or connection volume
How to Mitigate CVE-2025-43015
Immediate Actions Required
- Upgrade JetBrains RubyMine to version 2025.1 or later on all developer endpoints
- Audit developer workstations for RubyMine processes listening on non-loopback interfaces and terminate exposed sessions
- Restrict developer subnet access using host-based firewalls to block inbound traffic to IDE ports
Patch Information
JetBrains resolved this issue in RubyMine 2025.1. Details are published in the JetBrains Security Issues Fixed advisory. Administrators should deploy the fixed version through JetBrains Toolbox or centralized software distribution and verify the version string via rubymine --version.
Workarounds
- Disable the remote interpreter feature until the RubyMine upgrade is applied
- Enforce host firewall rules that permit inbound connections only from 127.0.0.1 on RubyMine-owned ports
- Place developer workstations on segmented networks that block peer-to-peer connectivity to IDE ports
# Example host firewall rule to block non-loopback access to RubyMine ports on Linux
sudo iptables -A INPUT -i lo -p tcp --dport 0:65535 -j ACCEPT
sudo iptables -A INPUT -p tcp -m owner --uid-owner developer -j DROP
# Verify RubyMine listening sockets
ss -tlnp | grep -i rubymine
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
