Critical Vulnerability in IBM API Connect (CVE-2025-13915) Enables Remote Authentication Bypass and Unauthorized Access

Executive Summary

IBM has issued a critical security advisory regarding a severe vulnerability in its API Connect platform, identified as CVE-2025-13915. This vulnerability enables remote, unauthenticated attackers to bypass authentication controls, granting them unauthorized access to sensitive management interfaces and APIs. With a CVSS v3.1 base score of 9.8 (Critical), this flaw represents a significant risk to organizations leveraging IBM API Connect for API management and integration. Although there is currently no evidence of exploitation in the wild, the ease of exploitation and the criticality of the affected product make this a high-priority issue for all organizations using the impacted versions. Immediate remediation is strongly advised to prevent potential compromise of data, integrity, and service availability.

Technical Information

The vulnerability, tracked as CVE-2025-13915, is classified under CWE-305: Authentication Bypass by Primary Weakness. The flaw arises from improper authentication checks within the IBM API Connect platform, specifically affecting the management interface and potentially any exposed APIs. Attackers can exploit this weakness remotely, over the network, without requiring any user interaction or valid credentials.

The attack vector is network-based, with low attack complexity and no prerequisites for privileges or user interaction. The vulnerability allows for a complete compromise of confidentiality, integrity, and availability, as denoted by the CVSS vector string AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

The technical root cause is a failure in the authentication logic, which can be triggered by sending specially crafted requests to the API Connect management endpoints. This bypasses the intended authentication flow, allowing attackers to interact with the system as if they were authenticated users. The impact is particularly severe in environments where the management interface is exposed to the internet or untrusted networks.

IBM API Connect is widely used for API lifecycle management, including design, testing, deployment, and monitoring of APIs. The platform is often integrated with critical business systems, making any compromise potentially catastrophic. Attackers exploiting this vulnerability could gain access to sensitive configuration data, manipulate API definitions, exfiltrate data, or disrupt API services.

The affected versions, as confirmed by the IBM Security Bulletin, include IBM API Connect 10.0.8.0, 10.0.8.1, 10.0.8.2, 10.0.8.3, 10.0.8.4, 10.0.8.5, and 10.0.11.0. The vulnerability is present in both on-premises and cloud deployments, increasing the attack surface for organizations with hybrid or multi-cloud architectures.

The absence of robust authentication checks in these versions means that any exposed management interface is at risk. Attackers can enumerate endpoints, escalate privileges, and potentially pivot to other internal systems if network segmentation is insufficient. The vulnerability is particularly dangerous in environments where API Connect is used to broker access between internal and external services, as it could serve as a gateway for broader compromise.

Exploitation in the Wild

As of the latest available intelligence, there are no confirmed reports of active exploitation of CVE-2025-13915 in the wild. Security researchers and vendors are closely monitoring for the emergence of proof-of-concept (PoC) exploit code, which could accelerate the weaponization of this vulnerability.

Historically, similar authentication bypass vulnerabilities in enterprise platforms have been rapidly adopted by threat actors once public exploit code becomes available. The low complexity of this attack, combined with the high value of the targeted systems, makes it likely that exploitation attempts will follow soon after public disclosure and patch release.

Organizations should remain vigilant for signs of exploitation, including unauthorized access attempts, anomalous API calls, and unexpected changes to API configurations. The lack of current exploitation should not be interpreted as a reduced risk; rather, it underscores the importance of proactive mitigation before threat actors can operationalize this vulnerability.

APT Groups using this vulnerability

At this time, there are no public attributions linking any known Advanced Persistent Threat (APT) groups or cybercriminal organizations to the exploitation of CVE-2025-13915. However, the nature of the vulnerability aligns with tactics commonly employed by APT groups and ransomware operators, particularly those focused on initial access and lateral movement within enterprise environments.

Previous authentication bypass vulnerabilities in similar platforms have been leveraged by groups such as FIN11, Conti, and various state-sponsored actors for initial access, data exfiltration, and ransomware deployment. The MITRE ATT&CK techniques most relevant to this vulnerability are T1190: Exploit Public-Facing Application and T1078: Valid Accounts, should attackers use the bypass to create or abuse accounts post-exploitation.

Given the high value of IBM API Connect deployments in sectors such as finance, healthcare, and telecommunications, it is highly probable that sophisticated threat actors will seek to exploit this vulnerability once reliable exploit methods are available. Organizations should monitor threat intelligence feeds and vendor advisories for updates on active exploitation and emerging threat actor activity.

Affected Product Versions

The following versions of IBM API Connect are confirmed to be affected by CVE-2025-13915:

IBM API Connect 10.0.8.0, IBM API Connect 10.0.8.1, IBM API Connect 10.0.8.2, IBM API Connect 10.0.8.3, IBM API Connect 10.0.8.4, IBM API Connect 10.0.8.5, and IBM API Connect 10.0.11.0.

Both on-premises and cloud-based deployments are impacted. Organizations running any of these versions should consider themselves at risk and take immediate action to remediate the vulnerability.

Workaround and Mitigation

The primary mitigation for CVE-2025-13915 is to apply the latest interim fixes (iFixes) provided by IBM for the affected versions of API Connect. IBM has released patches for all impacted versions, which can be obtained from the following official sources:

For IBM API Connect 10.0.8.x, the relevant iFixes are available at https://www.ibm.com/support/pages/node/7255318. For IBM API Connect 10.0.11.0, the iFix can be found at https://ibm.biz/BdbtCw.

If immediate patching is not feasible, IBM recommends disabling self-service sign-up on the Developer Portal to reduce the attack surface. This workaround limits the exposure of the authentication bypass vector but does not fully mitigate the risk. Organizations should also restrict network access to the management interface, implement strong access controls, and monitor for anomalous activity.

IBM’s official guidance states: "IBM strongly recommends addressing the vulnerability now by upgrading. Customers unable to install the interim fix should disable self-service sign-up on their Developer Portal if enabled, which will help minimise their exposure to this vulnerability."

In addition to patching and workarounds, organizations should review access logs for signs of unauthorized access, unexpected account creation, or privilege escalation events. Enhanced monitoring of API traffic and management interface activity is advised until full remediation is confirmed.

References

IBM Security Bulletin: Authentication bypass in IBM API Connect (CVE-2025-13915): https://www.ibm.com/support/pages/security-bulletin-authentication-bypass-ibm-api-connect-0

The Hacker News: IBM Warns of Critical API Connect Bug Allowing Remote Authentication Bypass: https://thehackernews.com/2025/12/ibm-warns-of-critical-api-connect-bug.html

BleepingComputer: IBM warns of critical API Connect auth bypass vulnerability: https://www.bleepingcomputer.com/news/security/ibm-warns-of-critical-api-connect-auth-bypass-vulnerability/

NVD Entry for CVE-2025-13915: https://nvd.nist.gov/vuln/detail/CVE-2025-13915

MITRE ATT&CK T1190: Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/

Rescana is here for you

At Rescana, we understand the critical importance of timely and actionable threat intelligence in today’s rapidly evolving cyber landscape. Our Third-Party Risk Management (TPRM) platform empowers organizations to continuously monitor, assess, and mitigate risks across their digital supply chain. While this advisory focuses on a specific vulnerability in IBM API Connect, our platform is designed to provide comprehensive visibility and proactive defense against a wide range of cyber threats.

If you have any questions about this advisory or require further assistance in assessing your exposure, please contact us at ops@rescana.com. Our team of cybersecurity experts is ready to support you in safeguarding your organization’s digital assets.