CyberSecBulletin
CVE-2023-29525NVD status: Modified

xwiki-platform: Improper Neutralization of Special Elements in Output Used by a Downstream Component

CVE-2023-29525 is a high-severity improper neutralization of special elements in output used by a downstream component 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: < 14.4.8; >= 14.5.0, < 14.10.3.. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 77.8% chance of exploitation within 30 days, which is in the top 0.42% 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 14.4.8 or 14.10.3, 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< 14.4.8; >= 14.5.0, < 14.10.3.Not stated
XWikiXwikibefore 14.4.8; 14.5 up to, but not including, 14.10.314.4.8, 14.10.3

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
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. Affected versions of xwiki are subject to code injection in the `since` parameter of the `/xwiki/bin/view/XWiki/Notifications/Code/LegacyNotificationAdministration` endpoint. This provides an XWiki syntax injection attack via the since-parameter, allowing privilege escalation from view to programming rights and subsequent code execution privilege. The vulnerability has been patched in XWiki 15.0-rc-1, 14.10.3, 14.4.8 and 14.10.3. Users are advised to upgrade. Users unable to upgrade may modify the page `XWiki.Notifications.Code.LegacyNotificationAdministration` to add the missing escaping. For versions < 14.6-rc-1 a workaround is to modify the file `<xwikiwebapp>/templates/distribution/eventmigration.wiki` to add the missing escaping.

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

The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

How developers prevent this class of flaw

  • Programming languages and supporting technologies might be chosen which are not subject to these issues.
  • Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.

More Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities (CWE-74)

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 Special Elements in Output Used by a Downstream Component vulnerabilities

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