CVE-2025-15099 is an improper authentication vulnerability found in simstudioai's sim software up to version 0.5.27. The flaw exists in the CRON Secret Handler component, specifically within the file apps/sim/lib/auth/internal.ts. The vulnerability is triggered by manipulation of the INTERNAL_API_SECRET argument, which is intended to secure internal API calls. Due to improper validation or handling of this secret, attackers can remotely bypass authentication mechanisms without requiring any privileges or user interaction. This allows unauthorized remote access to internal APIs or functions that should be protected. The vulnerability has a CVSS 4.0 base score of 6.9 (medium severity), reflecting its network attack vector, low complexity, and no required privileges or user interaction. The impact on confidentiality, integrity, and availability is rated low individually but combined could lead to unauthorized data access or modification and potential service disruption. The exploit code is publicly available, increasing the risk of exploitation, although no active exploitation has been reported yet. The vendor has released a patch identified by commit e359dc2946b12ed5e45a0ec9c95ecf91bd18502a, which addresses the improper authentication by correcting the handling of the INTERNAL_API_SECRET. Organizations using affected versions should apply this patch promptly to mitigate the risk. The vulnerability is particularly relevant for deployments exposing internal APIs or relying on simstudioai sim for critical AI or simulation workloads.

For European organizations, this vulnerability poses a risk of unauthorized remote access to internal APIs within simstudioai sim deployments. This can lead to unauthorized data disclosure, modification, or disruption of services relying on the sim platform. Organizations in sectors such as AI research, software development, telecommunications, and critical infrastructure that utilize simstudioai sim could face operational impacts or data breaches. The lack of required privileges or user interaction lowers the barrier for attackers, increasing the likelihood of exploitation if unpatched. While the direct impact on confidentiality, integrity, and availability is rated low individually, combined effects could allow attackers to pivot within networks or compromise sensitive internal functions. This could undermine trust in AI simulation environments and cause compliance issues under European data protection regulations such as GDPR if personal or sensitive data is involved. The availability of public exploit code further elevates the threat level, necessitating urgent patching and monitoring. Failure to address this vulnerability could result in reputational damage and financial losses for affected organizations.

1. Immediately apply the vendor-provided patch identified by commit e359dc2946b12ed5e45a0ec9c95ecf91bd18502a to all affected simstudioai sim instances running versions up to 0.5.27. 2. Restrict network access to internal APIs and the CRON Secret Handler component by implementing strict firewall rules and network segmentation to limit exposure. 3. Rotate and securely manage any secrets or API keys related to INTERNAL_API_SECRET to prevent reuse of compromised credentials. 4. Implement robust monitoring and logging of authentication attempts and API access to detect anomalous or unauthorized activities promptly. 5. Conduct regular security assessments and code reviews focusing on authentication mechanisms within simstudioai sim deployments. 6. Educate development and operations teams about the risks of improper secret handling and enforce secure coding practices. 7. If possible, deploy Web Application Firewalls (WAFs) or API gateways with anomaly detection to block suspicious requests targeting internal APIs. 8. Maintain an incident response plan tailored to vulnerabilities in AI simulation platforms to enable rapid containment and remediation.