CVE-2026-7300

Executive Summary

CVE-2026-7300 is a critical buffer overflow vulnerability in RTI Connext Professional's Web Integration Service. The flaw allows an attacker to cause a filter failure through a classic buffer overflow, potentially leading to remote code execution or denial of service. The vulnerability affects multiple versions of Connext Professional, including 6.1.2 to 6.1., 7.0.0 to 7.3.1.3, and 7.4.0 to 7.. No public proof-of-concept or exploit code is available at this time, but the risk is significant due to the widespread use of RTI Connext in industrial and critical infrastructure environments.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary middleware product (RTI Connext Professional) used in distributed systems, particularly in industrial IoT and real-time data distribution.

CVSS Breakdown & Threat Level

The CVSS score is currently 0.0, indicating that no official CVSS vector has been assigned. However, based on the nature of the vulnerability (buffer overflow in a network service), the likely impact is high. A reasonable estimated vector would be:

• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: High (A:H)

Estimated CVSS Score: 9.8 (Critical)

Deep Dive & Mechanics

The vulnerability resides in the Web Integration Service (WIS) component of RTI Connext Professional. The WIS is responsible for bridging HTTP/HTTPS traffic to the DDS (Data Distribution Service) middleware. A classic buffer overflow occurs when the service copies data into a fixed-size buffer without proper bounds checking. An attacker can send a specially crafted HTTP request with an oversized payload, causing the buffer to overflow and overwrite adjacent memory. This can lead to arbitrary code execution or service crash.

The root cause is a lack of input validation in the buffer copy routine. The vulnerable code likely uses functions like strcpy() or memcpy() without checking the source length against the destination buffer size. The overflow can corrupt critical data structures, including function pointers or return addresses, enabling control flow hijacking.

Vulnerable vs. Patched Code

Vulnerable Code (C example):

void handle_request(char *input) {
    char buffer[256];
    strcpy(buffer, input); // No bounds checking
    // Process buffer...
}

Patched Code (C example):

void handle_request(char *input) {
    char buffer[256];
    strncpy(buffer, input, sizeof(buffer) - 1);
    buffer[sizeof(buffer) - 1] = '\0'; // Ensure null termination
    // Process buffer...
}

The patched version uses strncpy() with a size limit and ensures null termination, preventing buffer overflow.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install RTI Connext Professional 7.0.0 on a Linux VM.
2. Enable the Web Integration Service on port 8080.
3. Use a tool like netcat or python to send oversized HTTP requests.

Exploit Attempt (Python):

import socket

target_ip = "192.168.1.100"
target_port = 8080

# Craft an oversized payload
payload = b"A" * 1000  # Adjust size to trigger overflow

# Send HTTP request
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((target_ip, target_port))
sock.send(b"GET /" + payload + b" HTTP/1.1\r\nHost: example.com\r\n\r\n")
sock.close()

Note: No public exploit code is available. The above is a generic example for testing.

Blue Team

Detection:

• Monitor for unusually large HTTP request payloads to the Web Integration Service.
• Use network intrusion detection systems (NIDS) to flag oversized requests.
• Enable logging on the WIS and review for buffer overflow errors or crashes.

Mitigation:

• Apply vendor patches immediately.
• Restrict network access to the WIS using firewalls.
• Implement input validation and size limits at the application layer.

Indicators of Compromise (IOCs)

• Network: HTTP requests with payloads exceeding 256 bytes to the WIS endpoint.
• Logs: Error messages indicating buffer overflow or segmentation faults in the WIS logs.
• System: Unexpected crashes or restarts of the Connext Professional service.
• Memory: Corrupted memory regions in the WIS process.

Detection Engineering

YARA Rule

rule CVE_2026_7300_Buffer_Overflow {
    meta:
        description = "Detects buffer overflow attempts in RTI Connext Web Integration Service"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2026-7300"
    strings:
        $overflow = /GET \/{1000,} HTTP\/1\.1/  // Matches requests with >1000 characters
        $error = "buffer overflow" nocase
    condition:
        $overflow or $error
}

Sigma Rule

title: CVE-2026-7300 Buffer Overflow Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects oversized HTTP requests targeting RTI Connext Web Integration Service
author: Valters IT
logsource:
    category: webserver
    product: rti_connext
detection:
    selection:
        http_method: "GET"
        http_uri|length: > 256
    condition: selection
falsepositives:
    - Legitimate large requests (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2026-7300 Buffer Overflow Attempt"; flow:to_server; content:"GET"; http_method; content:"/"; http_uri; pcre:"/^.{257,}/R"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Upgrade to patched versions (6.1., 7.3.1.3, or 7.) as per vendor advisory.
2. Network: Restrict access to the Web Integration Service to trusted IPs only.
3. Monitoring: Enable detailed logging and alert on oversized HTTP requests.
4. WAF: Deploy a web application firewall to filter malicious payloads.
5. Backup: Ensure backups are available in case of service disruption.

Valters IT
Securing Digital Frontiers