Description

Contributor Remote Code Execution (RCE) in Betheme <= 28.4.2 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.9",
  "pubDate": "2026-08-06T15:17:16.737Z",
  "pubdate": "2026-08-06T15:17:16.737Z",
  "executiveSummary": "A Remote Code Execution (RCE) vulnerability exists in Betheme versions 28.4.2 and prior, specifically impacting low-privileged user roles such as contributors. This security flaw allows authenticated users with minimal privileges to execute arbitrary code on the underlying hosting server. The vulnerability poses a severe risk to the confidentiality, integrity, and availability of the affected web application. An attacker possessing contributor-level access can leverage this flaw to bypass application-level restrictions and achieve full system compromise. Successful exploitation requires valid authentication credentials corresponding to a user role with contributor privileges or higher. The root cause stems from insufficient input validation and insecure handling of executable components within the theme functionality. Mitigation requires immediate updating of the Betheme product to a patched version once available, alongside stringent access control enforcement and monitoring of user role assignments within the content management system.",
  "technicalDetails": "The vulnerability resides within the Betheme codebase, specifically targeting functionality accessible to users with the contributor role in versions 28.4.2 and below. The root cause involves inadequate sanitization and validation of user-supplied input or insecure processing of files and parameters handled by the theme's backend mechanisms. In typical WordPress environments, the contributor role is heavily restricted and lacks the capability to publish posts or upload arbitrary files. However, improper capability checks or logic flaws within the vulnerable component of Betheme permit low-privileged users to interact with sensitive functions intended for administrators or editors.\nThe attack flow begins when an authenticated attacker with contributor privileges crafts a malicious HTTP request directed at the vulnerable theme endpoints or parameters. Due to insufficient authorization enforcement or improper input filtering, the application processes the untrusted input insecurely. This allows the attacker to inject malicious payloads—typically PHP code or serialized data—into the application context.\nUpon successful processing by the vulnerable component, the application executes the injected instructions within the security context of the web server process. The network exposure is remote, requiring HTTP/HTTPS access to the target web application, coupled with active session credentials for a contributor-level account. Depending on the server configuration and file permissions, post-exploitation impact includes arbitrary command execution, unauthorized file read and write operations, database exfiltration, lateral movement within the hosting environment, and complete site takeover. The exploitation vector completely circumvents the intended privilege boundaries defined by the underlying content management system architecture, allowing privilege escalation from a restricted role to full remote code execution."
}