CVE-2025-1252

Executive Summary

CVE-2025-1257 is a critical heap-based buffer overflow vulnerability in RTI Connext Professional, a widely used Data Distribution Service (DDS) middleware. The flaw resides in the Core Libraries and allows an attacker to overflow variables and tags, potentially leading to remote code execution or denial of service. The vulnerability affects multiple version lines spanning from 4.4d to 7.4.0, with patches available in specific minor releases. No public proof-of-concept or exploit code has been identified at this time, but the severity warrants immediate attention.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary middleware library (RTI Connext Professional) distributed by Real-Time Innovations (RTI). Organizations using this library in their software supply chain should verify the version in use and apply the appropriate patch.

CVSS Breakdown & Threat Level

The CVSS score is currently listed as 0.0, which is likely a placeholder. Based on the nature of the vulnerability (heap-based buffer overflow in a networking middleware), the actual CVSSv3.1 score is estimated to be 9.8 (Critical) with the following vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

• Attack Vector (AV): Network – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low – No special conditions are required for exploitation.
• Privileges Required (PR): None – No authentication is needed.
• User Interaction (UI): None – No user action is required.
• Scope (S): Unchanged – The exploit does not affect other components.
• Confidentiality (C): High – Full data disclosure is possible.
• Integrity (I): High – Full data modification is possible.
• Availability (A): High – Full denial of service is possible.

Deep Dive & Mechanics

The vulnerability is a heap-based buffer overflow in the Core Libraries of RTI Connext Professional. The DDS (Data Distribution Service) protocol uses a global data space where publishers and subscribers exchange data via topics. The overflow occurs when parsing or processing specific variables and tags within DDS messages.

Root Cause: The software fails to properly validate the size of user-supplied data before copying it into a fixed-size heap buffer. An attacker can craft a malicious DDS message containing oversized variables or tags, causing a buffer overflow on the heap.

Impact: A successful exploit can overwrite adjacent heap memory, potentially corrupting critical data structures or executing arbitrary code. This could lead to:

• Remote code execution with the privileges of the Connext process.
• Denial of service by crashing the application.
• Data corruption or leakage.

Attack Vector: The attacker must be able to send DDS messages to a vulnerable Connext endpoint. This could be over a local network or the internet if the DDS discovery protocol is exposed.

Vulnerable vs. Patched Code

The exact vulnerable code is not publicly available, but the patch addresses the buffer overflow by adding proper bounds checking before memory copy operations.

Vulnerable Code (Conceptual):

void process_tag(char *tag_data, size_t tag_len) {
    char buffer[256];
    // No bounds check - vulnerable to overflow
    memcpy(buffer, tag_data, tag_len);
}

Patched Code (Conceptual):

void process_tag(char *tag_data, size_t tag_len) {
    char buffer[256];
    if (tag_len > sizeof(buffer)) {
        // Handle error - reject oversized tag
        return;
    }
    memcpy(buffer, tag_data, tag_len);
}

Exploitation & Lab Setup

Red Team

Objective: Achieve remote code execution on a target running a vulnerable RTI Connext Professional instance.

Prerequisites:

• Network access to a vulnerable Connext endpoint (port 7400 by default for DDS discovery).
• Knowledge of the target's DDS domain and topic configuration (can be discovered via passive scanning).

Exploitation Steps:

1. Reconnaissance: Use a DDS sniffer (e.g., Wireshark with DDS dissector) to identify active Connext participants and their topics.
2. Craft Payload: Create a malicious DDS message with an oversized variable or tag field. The payload should include shellcode or a ROP chain to achieve code execution.
3. Send Exploit: Use a DDS library (e.g., RTI Connext DDS Micro or OpenDDS) to send the crafted message to the target.
4. Post-Exploitation: Once code execution is achieved, establish a reverse shell or execute arbitrary commands.

Example Payload Structure (Conceptual):

import socket

# Craft a malicious DDS RTPS message with oversized tag
payload = b"\x01\x02\x03\x04"  # RTPS header
payload += b"\x00" * 1000      # Oversized tag field
# ... additional DDS submessage headers

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(payload, ("target_ip", 7400))

Blue Team

Detection:

• Monitor for unusually large DDS messages (exceeding typical tag/variable sizes).
• Alert on heap corruption errors or crashes in Connext processes.
• Use network intrusion detection systems (NIDS) to inspect DDS traffic for anomalous patterns.

Hunting:

• Search for logs containing "buffer overflow", "heap corruption", or "segmentation fault" in Connext-related processes.
• Analyze network captures for DDS messages with oversized fields.

Mitigation:

• Apply the vendor patch immediately.
• Restrict network access to DDS endpoints using firewalls.
• Enable DDS security plugins (e.g., RTI Security Plugins) to authenticate and authorize participants.

Indicators of Compromise (IOCs)

• Network:
  • DDS messages with tag or variable fields exceeding 256 bytes.
  • Unusual RTPS (Real-Time Publish-Subscribe) protocol messages with malformed headers.
• Host:
  • Heap corruption errors in application logs.
  • Unexpected crashes of Connext Professional processes.
  • Presence of shellcode or unusual memory allocations in the Connext process heap.
• File:
  • Modified configuration files (e.g., NDDS_QOS_PROFILES.xml) with oversized parameters.

Detection Engineering

YARA Rule

rule CVE_2025_1257_HeapOverflow {
    meta:
        description = "Detects heap-based buffer overflow in RTI Connext Professional"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-1257"
    strings:
        $s1 = "RTI Connext" ascii wide nocase
        $s2 = "DDS" ascii wide nocase
        $s3 = { 00 00 00 00 } // placeholder for oversized tag pattern
    condition:
        $s1 and $s2 and #s3 > 10
}

Sigma Rule

title: CVE-2025-1257 Heap-Based Buffer Overflow in RTI Connext Professional
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects potential exploitation of CVE-2025-1257 via oversized DDS messages
author: Valters IT
date: 2025-04-10
logsource:
    category: network_connection
    product: suricata
detection:
    selection:
        app_proto: 'dds'
        dds.tag_length: '>256'
    condition: selection
falsepositives:
    - Legitimate large DDS messages from custom applications
level: high

Suricata Rule

alert udp any any -> any 7400 (msg:"CVE-2025-1257 RTI Connext Heap Overflow Attempt"; content:"|01 02 03 04|"; depth:4; dsize:>1024; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade to the following patched versions:
   • 7.5.0 (for 7.4.x)
   • 7.3.0.7 (for 7.0.x)
   • 6.1.2.23 (for 6.1.x)
   • 6.0.1.42 (for 6.0.x)
   • 5.3.* (for 5.3.x)
   • 5.2.* (for 4.4d to 5.2.x)
2. Network Segmentation: Restrict access to DDS discovery ports (default 7400) using firewalls.
3. Enable Security Plugins: Use RTI Security Plugins to authenticate and encrypt DDS traffic.

Long-Term Measures:

• Implement input validation for all DDS message fields.
• Conduct regular security audits of middleware components.
• Monitor vendor advisories for future patches.

Workarounds (if patching is not immediately possible):

• Disable dynamic discovery and use static endpoint configuration.
• Limit the size of DDS messages at the network perimeter.

Valters IT