CVE intelligence and bounded remediation

CVE-2021-38753 — Simple Image Gallery Web App Project Simple Image Gallery Web App security vulnerability

Critical CVSS 9.8

An unrestricted file upload on Simple Image Gallery Web App can be exploited to upload a web shell and executed to gain unauthorized access to the server hosting the web app.

Severity
Critical
CVSS
9.8 (3.1)
Published
2021-08-16
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-434

Affected products

  • simple_image_gallery_web_app_project / simple_image_gallery_web_app

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.