CVE-2025-1329 is a high-severity vulnerability classified as CWE-787 (Out-of-bounds Write) affecting IBM CICS TX Standard 11.1 and IBM CICS TX Advanced versions 10.1 and 11.1. The vulnerability arises from improper handling of DNS return requests by the gethostbyaddr function. Specifically, a local user can exploit this flaw to perform an out-of-bounds write operation, which may lead to arbitrary code execution on the affected system. The vulnerability requires local access with low privileges (PR:L) and does not require user interaction (UI:N). The attack complexity is low (AC:L), meaning exploitation is feasible without specialized conditions. The vulnerability impacts confidentiality, integrity, and availability (all rated high), indicating that successful exploitation could allow an attacker to fully compromise the system, execute arbitrary code, and potentially disrupt services. IBM CICS TX is a transaction processing system widely used in enterprise environments, especially in mainframe and critical business applications. The vulnerability's root cause is a failure in the DNS resolution process, specifically in the gethostbyaddr function, which is responsible for resolving IP addresses to hostnames. An out-of-bounds write in this context can corrupt memory, leading to code execution under the privileges of the affected process. No known exploits are currently reported in the wild, but the high CVSS score (7.8) and the nature of the vulnerability suggest that it could be targeted by attackers with local access in the future. The lack of available patches at the time of publication increases the urgency for organizations to implement mitigation strategies.

For European organizations, the impact of CVE-2025-1329 is significant, particularly for those relying on IBM CICS TX Standard or Advanced for critical transaction processing. Successful exploitation could lead to full system compromise, allowing attackers to execute arbitrary code, steal sensitive data, manipulate transaction records, or disrupt business operations. Given the high confidentiality, integrity, and availability impacts, organizations could face severe operational disruptions, financial losses, and reputational damage. This is especially critical for sectors such as banking, insurance, telecommunications, and government agencies that depend heavily on IBM CICS TX for reliable transaction processing. The requirement for local access limits remote exploitation but does not eliminate risk, as insider threats or attackers who gain initial footholds through other means could leverage this vulnerability to escalate privileges and move laterally within networks. The absence of known exploits currently provides a window for proactive defense, but the vulnerability's characteristics warrant immediate attention to prevent future exploitation.

1. Restrict local access: Limit user permissions and access to systems running IBM CICS TX to only trusted and necessary personnel. Implement strict access controls and monitor for unusual local activity. 2. Network segmentation: Isolate systems running IBM CICS TX from general user networks to reduce the risk of unauthorized local access. 3. Monitor and audit: Enable detailed logging and monitoring of DNS resolution processes and local user activities to detect potential exploitation attempts early. 4. Apply principle of least privilege: Ensure that processes and users interacting with the gethostbyaddr function operate with minimal privileges necessary to reduce impact if exploited. 5. Prepare for patching: Although no patches are currently available, maintain close communication with IBM for updates and apply security patches promptly once released. 6. Incident response readiness: Develop and test incident response plans focused on local privilege escalation and code execution scenarios to minimize impact if exploitation occurs. 7. Use application whitelisting and memory protection mechanisms where possible to prevent arbitrary code execution resulting from memory corruption.