Description

A remote unauthorized attacker with network access via port 4307/TCP to the TrueConf server versions 5.3.X to 5.3.9, 5.4.X to 5.4.9, 5.5.X to 5.5.5, and earlier could execute an arbitrary script by calling an undocumented function.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-19T17:21:00.990Z",
  "pubdate": "2026-08-19T17:21:00.990Z",
  "executiveSummary": "An arbitrary script execution vulnerability has been identified in TrueConf Server versions 5.3.X to 5.3.9, 5.4.X to 5.4.9, 5.5.X to 5.5.5, and earlier.\nThe vulnerability allows a remote, unauthorized attacker with network access to execute arbitrary scripts via an undocumented function exposed by the application.\nThe primary impact of this flaw is complete compromise of the underlying application context, potentially allowing the execution of arbitrary commands or code depending on the server-side scripting environment.\nAffected systems include multiple iterations of TrueConf Server deployed across enterprise networks.\nThe risk implication is severe, as successful exploitation enables remote code execution without requiring prior authentication or valid user credentials.\nExploitation requirements are minimal, limited to network connectivity to the target host via port 4307/TCP and the ability to invoke the undocumented server function.",
  "technicalDetails": "The vulnerability resides in the server-side logic of TrueConf Server, specifically within an undocumented function accessible via the network service listening on port 4307/TCP.\nThe root cause stems from insufficient input validation and a lack of access control mechanisms governing the invocation of internal, undocumented application routines.\nBecause the function is exposed without requiring authentication or authorization checks, an unauthorized remote adversary can interact directly with the vulnerable component.\nThe attack flow begins when an attacker establishes a network connection to port 4307/TCP on the target TrueConf Server instance.\nThe attacker then transmits a specially crafted request designed to trigger the undocumented function, supplying a malicious script or payload as input parameters.\nUpon receiving the request, the vulnerable component fails to adequately sanitize or restrict the execution context, causing the application to process and execute the attacker-supplied script.\nThe affected versions include TrueConf Server 5.3.X through 5.3.9, 5.4.X through 5.4.9, 5.5.X through 5.5.5, and all preceding versions that incorporate the same undocumented function.\nNo privileges or authentication credentials are required to initiate the attack vector, elevating the threat level for internet-facing or internally exposed deployments.\nPost-exploitation impact includes unauthorized execution of arbitrary code within the security context of the TrueConf Server process, which can lead to further system compromise, data exfiltration, or lateral movement within the internal network."
}