Cyber Resilience

CVE-2024-39031

MediumPublic PoC

Published: 09 July 2024

Published
09 July 2024
Modified
05 June 2025
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0674 91.5th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-39031 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Silverpeas Silverpeas. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique JavaScript (T1059.007); ranked in the top 8.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

CVE-2024-39031 is a stored cross-site scripting vulnerability (CWE-79) affecting Silverpeas Core versions up to and including 6.3.5. It resides in the Mes Agendas calendar component, where event title and description fields lack proper output encoding when events are later rendered on user profile pages.

A low-privileged user can create a calendar event containing an XSS payload in the Titre or Description fields and invite any other user in the same domain, including administrators. When the invited victim subsequently views their own profile page, the payload executes in their browser context without any further interaction with the event itself, enabling theft of session tokens or other client-side actions.

A pull request addressing the issue has been published in the Silverpeas-Core repository. The EPSS score has remained flat at 0.0674 with no material increase since disclosure.

EU & UK References

Vulnerability details

In Silverpeas Core <= 6.3.5, in Mes Agendas, a user can create new events and add them to their calendar. Additionally, users can invite others from the same domain, including administrators, to these events. A standard user can inject an…

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XSS payload into the "Titre" and "Description" fields when creating an event and then add the administrator or any user to the event. When the invited user (victim) views their own profile, the payload will be executed on their side, even if they do not click on the event.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
T1555.003 Credentials from Web Browsers Credential Access
Adversaries may acquire credentials from web browsers by reading files specific to the target browser.
Why these techniques?

Stored XSS allows arbitrary JavaScript execution in any invited user's (including admin) browser context when viewing profile, calendar, or related pages, enabling JavaScript command execution, browser session hijacking, web session cookie theft, and credentials theft from web browsers to achieve privilege escalation.

Affected Assets

silverpeas
silverpeas
≤ 6.4

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References