Attack Chain

1. An unauthenticated attacker sends a crafted POST request to the Sparx Pro Cloud Server, including a model name within the binary blob (CVE-2026-42097).
2. The server improperly validates the request, failing to authenticate the user, and allowing the attacker to bypass authorization.
3. The attacker leverages the bypass to execute arbitrary SQL queries against the underlying database without proper authentication.
4. The attacker gains unauthorized access to sensitive data stored within the database, potentially reading, modifying, or deleting information.
5. In a separate attack, an attacker with low privilege access exploits a race condition (CVE-2026-42099) by creating a malicious PHP file within the repository.
6. The attacker sends a request to execute the malicious PHP file. Due to delayed transmission response, the file can be executed even after deletion.
7. The malicious PHP code executes arbitrary commands on the server, potentially installing malware or creating backdoors.
8. The attacker achieves full system compromise, enabling further malicious activities such as data exfiltration or lateral movement.

Impact

Successful exploitation of these vulnerabilities can lead to severe consequences. CVE-2026-42097 allows unauthenticated attackers to execute arbitrary SQL queries, potentially compromising sensitive data. CVE-2026-42098 allows attackers to bypass authentication and impersonate any user, leading to unauthorized modifications. CVE-2026-42099 enables arbitrary PHP code execution. CVE-2026-42100 can cause denial of service. The vulnerabilities collectively impact the confidentiality, integrity, and availability of affected systems. There is no mention of sectors targeted, or specific victim counts, but all users of unpatched Sparx Systems Pro Cloud Server and Enterprise Architect instances are at risk.

Recommendation

• Apply the latest patches for Sparx Systems Pro Cloud Server (<= 6.1 build 167) and Enterprise Architect (<= 17.1) to remediate the vulnerabilities detailed in this brief.
• Monitor web server logs for suspicious POST requests targeting Sparx Pro Cloud Server with model names in the binary blob, indicative of CVE-2026-42097 exploitation.
• Implement the Sigma rule “Detect Potential CVE-2026-42097 Exploitation Attempt” to identify potential exploitation attempts in web server logs.
• Monitor for the creation and execution of unusual PHP files in the Sparx Pro Cloud Server repository directory, potentially indicating CVE-2026-42099 exploitation.
• Deploy the Sigma rule “Detect Suspicious PHP File Creation in Sparx Pro Cloud Server Repository” to identify potentially malicious PHP files being created.