CVE intelligence and bounded remediation

CVE-2023-42803 — BigBlueButton is an open-source virtual classroom

High CVSS 8.8

BigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.2 is vulnerable to unrestricted file upload, where the insertDocument API call does not validate the given file extension before saving the file, and does not remove it in case of validation failures. BigBlueButton 2.6.0-beta.2 contains a patch. There are no known workarounds.

Severity
High
CVSS
8.8 (3.1)
Published
2023-10-30
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-434

Affected products

  • bigbluebutton / bigbluebutton
  • bigbluebutton / bigbluebutton / 2.6.0

Showing 2 representative product identities from 6 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

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

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