CyberSecBulletin
CVE-2023-29511NVD status: Modified

xwiki-platform: Improper Neutralization of Directives in Dynamically Evaluated Code

Published Updated By the CyberSecBulletin desk

CVE-2023-29511 is a high-severity improper neutralization of directives in dynamically evaluated code vulnerability in xwiki-platform from XWiki, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected xwiki-platform versions: >= 14.0-rc-1, < 14.4.8; >= 14.5, < 14.10.1; >= 1.5M2, < 13.10.11. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.04% chance of exploitation within 30 days, higher than 64% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Xwiki to 13.10.11 or 14.4.8 or 14.10.1, whichever matches your release line, or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
XWikixwiki-platform>= 14.0-rc-1, < 14.4.8; >= 14.5, < 14.10.1; >= 1.5M2, < 13.10.11Not stated
XWikiXwiki1.7 up to, but not including, 13.10.11; after 14.0 up to, but not including, 14.4.8; 14.5 up to, but not including, 14.10.1; 14.013.10.11, 14.4.8, 14.10.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.9CriticalCNA (github.com)
CVSS 3.18.8HighNVD

Official description

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user with edit rights on a page (e.g., it's own user page), can execute arbitrary Groovy, Python or Velocity code in XWiki leading to full access to the XWiki installation. The root cause is improper escaping of the section ids in `XWiki.AdminFieldsDisplaySheet`. This page is installed by default. The vulnerability has been patched in XWiki versions 15.0-rc-1, 14.10.1, 14.4.8, and 13.10.11.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Directives in Dynamically Evaluated Code

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes code syntax before using the input in a dynamic evaluation call (e.g. eval).

How developers prevent this class of flaw

  • If possible, refactor your code so that it does not need to use eval() at all.
  • For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures, so the python documentation discourages use of ast.literal_eval() on untrusted data.

More Improper Neutralization of Directives in Dynamically Evaluated Code vulnerabilities (CWE-95)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in xwiki-platform

All xwiki-platform vulnerabilities

Recent Improper Neutralization of Directives in Dynamically Evaluated Code vulnerabilities

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