CyberSecBulletin
CVE-2024-21650NVD status: Modified

xwiki-platform: Improper Control of Generation of Code

CVE-2024-21650 is a critical-severity improper control of generation of code vulnerability in xwiki-platform from XWiki, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected xwiki-platform versions: >= 2.2, < 14.10.17; >= 15.0-rc-1, < 15.5.3; >= 15.6-rc-1, < 15.8-rc-1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 93.5% chance of exploitation within 30 days, which is in the top 0.16% of all scored CVEs.

Patch now

Exploitation in the next 30 days is more likely than not, according to EPSS.

What to do

  1. Update Xwiki to 14.10.17 or 15.5.3, whichever matches your release line, or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
XWikixwiki-platform>= 2.2, < 14.10.17; >= 15.0-rc-1, < 15.5.3; >= 15.6-rc-1, < 15.8-rc-1Not stated
XWikiXwikibefore 14.10.17; 15.0 up to, but not including, 15.5.3; 15.6 through 15.714.10.17, 15.5.3

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
NoneNo account or login is needed.
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:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.110.0CriticalCNA (github.com)
CVSS 3.19.8CriticalNVD

Official description

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. XWiki is vulnerable to a remote code execution (RCE) attack through its user registration feature. This issue allows an attacker to execute arbitrary code by crafting malicious payloads in the "first name" or "last name" fields during user registration. This impacts all installations that have user registration enabled for guests. This vulnerability has been patched in XWiki 14.10.17, 15.5.3 and 15.8 RC1.

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

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

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 Control of Generation of Code vulnerabilities

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