CVE-2023-33176

mediumpriority · track · 26EPSS 0.005 · 41 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.47% (41st) EPSS
CVSS 6.5 · medium
Is it mine?
4 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · cert_bund

EPSS · scored 2026-10-28

BigBlueButton is an open source virtual classroom designed to help teachers teach and learners learn. In affected versions are affected by a Server-Side Request Forgery (SSRF) vulnerability. In an `insertDocument` API request the user is able to supply a URL from which the presentation should be downloaded. This URL was being used without having been successfully validated first. An update to the `followRedirect` method in the `PresentationUrlDownloadService` has been made to validate all URLs to be used for presentation download. Two new properties `presentationDownloadSupportedProtocols` and `presentationDownloadBlockedHosts` have also been added to `bigbluebutton.properties` to allow administrators to define what protocols a URL must use and to explicitly define hosts that a presentation cannot be downloaded from. All URLs passed to `insertDocument` must conform to the requirements of the two previously mentioned properties. Additionally, these URLs must resolve to valid addresses, and these addresses must not be local or loopback addresses. There are no workarounds. Users are advised to upgrade to a patched version of BigBlueButton.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.5
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 2.5
v3.14.8mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:Lsecondary · ENISA EU
v3.14.8mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:Lsecondary · security-advisories@github.comexploitability 2.2 · impact 2.5
v3.16mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-918US
04

affected products (4)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-1568BigBlueButton: Schwachstelle ermöglicht Manipulation von DatenDeutsch2023-06-26csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann eine Schwachstelle in BigBlueButton ausnutzen, um Daten zu manipulieren.

06

also known as (2)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdnvdcert_bundNVDCVE.orgMITRE
published 2023-06-26modified 2026-06-17
08

references (16)

External citations — patches, advisories, analysis.

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