CVE intelligence and bounded remediation

CVE-2020-5846 — Ahsay Cloud Backup Suite security vulnerability

High CVSS 8.8

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.

Severity
High
CVSS
8.8 (3.1)
Published
2020-01-06
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-434

Affected products

  • ahsay / cloud_backup_suite / 8.3.0.30

Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.