Security Resilience

CVE-2023-42803

Bigbluebutton ≤ 2.5.18

Published
30 October 2023
Modified
21 November 2024
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0054 44th percentile
Risk Priority 42 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-42803 is a medium-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Bigbluebutton Bigbluebutton. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

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…

more

of validation failures. BigBlueButton 2.6.0-beta.2 contains a patch. There are no known workarounds.

CWE(s)
CWE-434

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1011.001 Exfiltration Over Bluetooth Exfiltration
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-42804Same product: Bigbluebutton Bigbluebutton
CVE-2025-55200Same product: Bigbluebutton Bigbluebutton
CVE-2023-43797Same product: Bigbluebutton Bigbluebutton
CVE-2023-33176Same product: Bigbluebutton Bigbluebutton
CVE-2023-43798Same product: Bigbluebutton Bigbluebutton
CVE-2026-27736Same product: Bigbluebutton Bigbluebutton
CVE-2026-27467Same product: Bigbluebutton Bigbluebutton
CVE-2025-61602Same product: Bigbluebutton Bigbluebutton
CVE-2025-61601Same product: Bigbluebutton Bigbluebutton
CVE-2026-27466Same product: Bigbluebutton Bigbluebutton

Affected Assets

bigbluebutton
bigbluebutton
2.6.0 · ≤ 2.5.18

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.1.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

MP-7 Media Use
addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

SC-44 Detonation Chambers
addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

SC-51 Hardware-based Protection
addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

SI-3 Malicious Code Protection
addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 partial match
blocks

Hardened configuration baselines can enforce allowed file types and processing rules.

PR.PS-05 partial match
blocks

Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.

PR.PS-06 partial match
blocks

Secure development practices include input validation and file-type restrictions that prevent this weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.25 Assessment and decision on information security events partial match
removes

References