CVE-2024-28234 | Contao has insufficient BBCode sanitizer

Contao is an open source content management system. Starting in version 2.0.0 and prior to versions 4.13.40 and 5.3.4, it is possible to inject CSS styles via BBCode in comments. Installations are only affected if BBCode is enabled. Contao versions 4.13.40 and 5.3.4 have a patch for this issue. As a workaround, disable BBCode for comments.

Published: 2024-04-09 Last update: 2025-01-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-28234 is rated Moderate Risk (42.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.70%). Review affected assets and schedule remediation.

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-2024-28234

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 0.58% 0.70% +0.12%
2 2025-11-18 0.70% 0.58% -0.12%
3 2025-05-31 — 0.70% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-28234

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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: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.
 2.8 1.4 [email protected]
4.7 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2024-28234

GitHub Security Advisory for CVE-2024-28234

GHSA-j55w-hjpj-825g · Severity: medium · Ecosystem: composer — Contao: Insufficient BBCode sanitizer

Affected software / configurations for CVE-2024-28234

Vendor Product Version Raw CPE
contao contao >= 2.0, < 4.13.40 cpe:2.3:a:contao:contao:*:*:*:*:*:*:*:*
contao contao >= 5.0.0, < 5.3.4 cpe:2.3:a:contao:contao:*:*:*:*:*:*:*:*

References for CVE-2024-28234

cvelogic Threat Intelligence