Description

IBM Concert 1.0.0 through 2.3.1 could allow a remote attacker to perform unauthorized actions using man in the middle techniques due to improper certificate validation.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.9",
  "pubDate": "2026-08-28T22:16:45.913Z",
  "pubdate": "2026-08-28T22:16:45.913Z",
  "executiveSummary": "IBM Concert versions 1.0.0 through 2.3.1 are susceptible to a critical vulnerability arising from improper SSL/TLS certificate validation. This flaw allows a remote, network-adjacent attacker to perform Man-in-the-Middle (MitM) attacks by intercepting or spoofing encrypted communications.\nThe vulnerability type is classified as an improper certificate validation issue, which compromises the integrity and confidentiality of data in transit. Because the application fails to verify the authenticity of the presented server certificates, it becomes vulnerable to interception, manipulation, or unauthorized actions performed by an attacker positioned between the client and the server.\nThis vulnerability exposes the system to significant risk, as an attacker can masquerade as a trusted entity to gain unauthorized access or manipulate data flows. Successful exploitation requires the attacker to position themselves in the communication path (e.g., via ARP spoofing, DNS hijacking, or compromised network infrastructure). There are no specific authentication requirements for the attacker, as the flaw resides at the transport layer of the communication stack.\nThe primary risk implication is the potential for unauthorized execution of actions within the IBM Concert environment, as the trust model established by TLS/SSL protocols is effectively bypassed, rendering standard encrypted channels insecure against active interception.",
  "technicalDetails": "The vulnerability originates from the application's failure to perform rigorous validation of X.509 certificates during the TLS handshake process. Specifically, when IBM Concert establishes an outgoing connection or handles internal communication, the underlying logic fails to verify the certificate chain, expiration status, or identity match against the expected server hostname. This oversight effectively disables the security guarantees provided by TLS, allowing an attacker to present a self-signed or otherwise invalid certificate that the application blindly accepts as trusted.\nThe exploitation flow follows a standard Man-in-the-Middle pattern: 1. Network Interception: An attacker utilizes techniques such as ARP poisoning or router-based redirection to divert traffic intended for the IBM Concert communication channel through an attacker-controlled gateway. 2. Handshake Initiation: When the vulnerable IBM Concert component attempts to initiate a secure connection, the attacker intercepts the request and presents a malicious or spoofed certificate. 3. Certificate Acceptance: Because the application does not validate the certificate against a trusted Root Certificate Authority (CA) or check the identity attributes (Common Name or Subject Alternative Name), the handshake completes successfully, establishing an encrypted tunnel between the application and the attacker. 4. Traffic Manipulation: Once the secure tunnel is established, the attacker acts as a transparent proxy. The attacker can decrypt, inspect, and modify the application traffic in real-time before forwarding it to the legitimate destination, or perform unauthorized commands on behalf of the authenticated session.\nThis flaw is present in IBM Concert versions 1.0.0 through 2.3.1. The lack of validation occurs at the transport layer and affects all internal or external network communications reliant on these specific TLS implementations. The impact is severe, as it grants a remote attacker the capability to execute unauthorized actions, potentially leading to administrative command injection or sensitive data exfiltration, depending on the specific API endpoints or communication protocols being intercepted. Because the application treats the intercepted connection as legitimate, it provides no secondary validation checks to mitigate the lack of certificate integrity. Consequently, the attacker can conduct these operations without needing existing credentials, provided they can successfully position themselves within the network path to influence the traffic flow of the affected IBM Concert deployment."
}