xwiki-platform: Improper Encoding or Escaping of Output
CVE-2022-36100 is a high-severity improper encoding or escaping of output 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: >= 1.7, < 13.10.6; >= 14.0, < 14.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 73.6% chance of exploitation within 30 days, which is in the top 0.52% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Update Xwiki to 13.10.6 or 14.4, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| XWiki | xwiki-platform | >= 1.7, < 13.10.6; >= 14.0, < 14.4 | Not stated |
| XWiki | Xwiki | 1.7 up to, but not including, 13.10.6; 14.0 up to, but not including, 14.4 | 13.10.6, 14.4 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.9 | Critical | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
XWiki Platform Applications Tag and XWiki Platform Tag UI are tag applications for XWiki, a generic wiki platform. Starting with version 1.7 in XWiki Platform Applications Tag and prior to 13.10.6 and 14.4 in XWiki Platform Tag UI, the tags document `Main.Tags` in XWiki didn't sanitize user inputs properly. This allowed users with view rights on the document (default in a public wiki or for authenticated users on private wikis) to execute arbitrary Groovy, Python and Velocity code with programming rights. This also allowed bypassing all rights checks and thus both modification and disclosure of all content stored in the XWiki installation. The vulnerability could be used to impact the availability of the wiki. On XWiki versions before 13.10.4 and 14.2, this can be combined with CVE-2022-36092, meaning that no rights are required to perform the attack. The vulnerability has been patched in versions 13.10.6 and 14.4. As a workaround, the patch that fixes the issue can be manually applied to the document `Main.Tags` or the updated version of that document can be imported from version 14.4 of xwiki-platform-tag-ui using the import feature in the administration UI on XWiki 10.9 and later.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Encoding or Escaping of Output
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using the ESAPI Encoding control or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error. Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
- If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated. For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.
- Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
More Improper Encoding or Escaping of Output vulnerabilities (CWE-116)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/xwiki/xwiki-platform/security/advisories/GHSA-2g5c-228j-p52xExploit, Third Party Advisory
- jira.xwiki.org/browse/XWIKI-19747Exploit
Patches and release notes
- github.com/xwiki/xwiki-platform/commit/604868033ebd191cf2d1e94db336f0c4d9096427Third Party Advisory
Other vulnerabilities in xwiki-platform
- 7.1 High severity
- 8.2 High severity
- 7.5 High severity
- 9.3 Critical severity
- 8.6 High severity
- 7.5 High severity
Recent Improper Encoding or Escaping of Output vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 8.1 High severity
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