CVE-2023-5543 | Moodle: duplicating a bigbluebutton activity assigns the same meeting id

When duplicating a BigBlueButton activity, the original meeting ID was also duplicated instead of using a new ID for the new activity. This could provide unintended access to the original meeting.

Published: 2023-11-09 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-5543 is rated Low Risk (22.2/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.09%). Mandatory action: 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-2023-5543

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 2025-11-21 0.04% 0.09% +0.05%
2 2025-11-18 0.09% 0.04% -0.05%
3 2025-04-15 0.09%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-5543

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
1.8 1.4 [email protected]
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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.
1.8 1.4 [email protected]

Weakness enumeration for CVE-2023-5543

OS Trackers for CVE-2023-5543

vendor priority summary link
ubuntu medium CVE-2023-5543 medium priority: Ubuntu including 1 source packages (moodle), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 8, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2023-5543

Affected software / configurations for CVE-2023-5543

Vendor Product Version Raw CPE
moodle moodle >= 4.0.0, < 4.0.11 cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
moodle moodle >= 4.1.0, < 4.1.6 cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
moodle moodle >= 4.2.0, < 4.2.3 cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
fedoraproject extra_packages_for_enterprise_linux 7.0 cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:7.0:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*

References for CVE-2023-5543

cvelogic Threat Intelligence