CVE-2024-31981: XWiki Platform: Privilege escalation (PR) from user registration through PDFClass

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.4%, percentile 73: FIRST’s model estimates a 1.4% chance of exploitation activity in the next 30 days, higher than 73% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes org.xwiki.platform:xwiki-platform-oldcore (Maven) >= 3.0.1, < 14.10.20, fixed in 14.10.20; org.xwiki.platform:xwiki-platform-oldcore (Maven) >= 15.0-rc-1, < 15.5.4, fixed in 15.5.4; org.xwiki.platform:xwiki-platform-oldcore (Maven) >= 15.6-rc-1, < 15.10-rc-1, fixed in 15.10-rc-1. Check your lockfile, including transitive dependencies.

What it is

XWiki Platform is a generic wiki platform. Starting in version 3.0.1 and prior to versions 4.10.20, 15.5.4, and 15.10-rc-1, remote code execution is possible via PDF export templates. This vulnerability has been patched in XWiki 14.10.20, 15.5.4 and 15.10-rc-1. If PDF templates are not typically used on the instance, an administrator can create the document XWiki.PDFClass and block its edition, after making sure that it does not contain a style attribute. Otherwise, there are no known workarounds aside from upgrading.

From the GitHub advisory

Impact Remote code execution is possible via PDF export templates. To reproduce on an installation, register a new user account with username PDFClass if XWiki.PDFClass does not exist. On XWiki.PDFClass, use the class editor to add a "style" property of type "TextArea" and content type "Plain Text". Then, add an object of class PDFClass and set the "style" attribute to $services.logging.getLogger('PDFClass').error("I got programming: $services.security.authorization.hasAccess('programming')"). Finally, go to /xwiki/bin/export/Main/WebHome?format=pdf&pdftemplate=XWiki.PDFClass. If the logs contain "ERROR PDFClass - I got programming: true", the instance is vulnerable.

Patches This vulnerability has been patched in XWiki 14.10.20, 15.5.4 and 15.10-rc-1.

Workarounds If PDF templates are not typically used on the instance, an administrator can create the document XWiki.PDFClass and block its edition, after making sure that it does not contain a style attribute. Otherwise, the instance needs to be updated.

References - https://jira.xwiki.org/browse/XWIKI-21337 - https://github.com/xwiki/xwiki-platform/commit/d28e21a670c69880b951e415dd2ddd69d273eae9

Weakness type: CWE-862.

Product: org.xwiki.platform:xwiki-platform-oldcore (Maven) · Assigned by: GitHub_M · Published: 2024-04-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.45% probability of exploitation activity in the next 30 days; percentile 73.

Timeline

• 2024-04-10 — CVE record published by GitHub_M
• 2024-04-10 — GitHub-reviewed advisory GHSA-vxwr-wpjv-qjq7 published (critical)
• 2024-08-13 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-vxwr-wpjv-qjq7 github.com
2. CVE.org record CVE-2024-31981 cve.org
3. NVD entry CVE-2024-31981 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. jira.xwiki.org jira.xwiki.org

Critical Maven advisories · Today’s Security Digest