CVE-2023-5551 | Moodle: forum summary report shows students from other groups when in separate groups mode

Separate Groups mode restrictions were not honoured in the forum summary report, which would display users from other groups.

Published: 2023-11-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-5551 is rated Low Risk (20.2/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.28%). 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-2023-5551

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 2026-06-15 0.07% 0.28% +0.20%
2 2025-11-21 0.04% 0.07% +0.03%
3 2025-11-18 0.04%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-5551

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:N/I:L/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
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-2023-5551

GitHub Security Advisory for CVE-2023-5551

GHSA-jr83-8x65-xcr5 · Severity: low · Ecosystem: composer — Moodle Exposure of Sensitive Information to an Unauthorized Actor vulnerability

OS Trackers for CVE-2023-5551

vendor priority summary link
ubuntu medium CVE-2023-5551 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-2023-5551

Affected software / configurations for CVE-2023-5551

Vendor Product Version Raw CPE
moodle moodle < 3.9.24 cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
moodle moodle >= 3.11.0, < 3.11.17 cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
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-2023-5551

cvelogic Threat Intelligence