CVE-2023-33176
Blind SSRF When Uploading Presentation in BigBlueButton
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Timeline
ID reserved
By GitHub_M
- 40 days later
· 40 days later
Published
- 17 months later
· 17 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.47% · top 59% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.8.
Weakness
Affected products
- affected >= 2.6.0, < 2.6.9
- affected < 2.5.18
References (5)
- https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-3q22-hph2-cff7 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/bigbluebutton/bigbluebutton/pull/18045 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/bigbluebutton/bigbluebutton/pull/18052 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/bigbluebutton/bigbluebutton/commit/43394dade595d0707384e4878357901537352415 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/bigbluebutton/bigbluebutton/commit/b18aff32e65a47f1eb2c800e86dcfc7a8fb05e71 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-33176)Record last updated .