CVE-2023-42804 | BigBlueButton Path Traversal – Reading Certain File Extensions

BigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.1 has a path traversal vulnerability that allows an attacker with a valid starting folder path, to traverse and read other files without authentication, assuming the files have certain extensions (txt, swf, svg, png). In version 2.6.0-beta.1, input validation was added on the parameters being passed and dangerous characters are stripped. There are no known workarounds.

Published: 2023-10-30 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-42804 is rated Low Risk (28.6/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.24%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-42804

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-08-25 0.25% 0.24% -0.01%
2 2025-03-17 0.06% 0.25% +0.19%
3 2024-09-29 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-42804

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-42804

Affected software / configurations for CVE-2023-42804

Vendor Product Version Raw CPE
bigbluebutton bigbluebutton <= 2.5.18 cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.6.0 cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha1:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.6.0 cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha2:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.6.0 cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha3:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.6.0 cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha4:*:*:*:*:*:*

References for CVE-2023-42804

cvelogic Threat Intelligence