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Unrestricted Upload of File with Dangerous Type

CVE-2020-5846

Medium
4/10

Summary

An insecure file upload and code execution issue was discovered in Ahsay Cloud Backup Suite 8.3.0.30 via a "PUT /obs/obm7/file/upload" request with the base64-encoded pathname in the X-RSW-custom-encode-path HTTP header, and the content in the HTTP request body. It is possible to upload a file into any directory of the server. One can insert a JSP shell into the web server's directory and execute it. This leads to full system access as the configured user (e.g., Administrator) when starting from any authenticated session (e.g., a trial account). This is fixed in the 83/830122/cbs-*-hotfix-task26000 builds.

  • LOW
  • NETWORK
  • SINGLE
  • PARTIAL
  • NONE
  • NONE

CWE-434 - Unrestricted Upload of File with dangerous type

'Unrestricted file upload with dangerous type' attacks involve an attacker uploading or transferring files of dangerous types to the server. The severity of such an attack depends upon the execution mechanism and the storage location of the uploaded file. Thus, it may range from simple defacement to arbitrary file execution, and complete system takeover.

References

Advisory Timeline

  • Published