Headline
GHSA-52vf-hvv3-98h7: xwiki vulnerable to Improper Handling of Exceptional Conditions
Impact
Users with write rights can insert well-formed content that is not handled well by the parser. For instance, with xwiki/2.1, inserting a deeply nested group blocks (((( ((( ((( ((( .... ))) ))) ))) ))) (see the generator below to produce a large payload) can lead to the parser throwing a StackOverflowError.
As a consequence, some pages becomes unusable, including:
- the user index (if the page containing the faulty content is a user page)
- the page index
Note that on the page, the normal UI is completely missing and it is not possible to open the editor directly to revert the change as the stack overflow is already triggered while getting the title of the document. This means that it is quite difficult to remove this content once inserted.
Patches
This has been patched on XWiki 13.10.10, 14.4.6, and 14.9-rc-1.
Workarounds
A temporary solution to avoid Stack Overflow errors is to increase the memory allocated to the stack by using the -Xss JVM parameter (e.g., -Xss32m). This should allow the parser to pass and to fix the faulty content.
Note that we did not evaluated the consequence on other aspects of the system (e.g., performances), and should be only be used as a temporary solution.
Also, this does not prevent the issue to occur again with another content.
Consequently, it is strongly advised to upgrade to a version where the issue has been patched.
References
- https://jira.xwiki.org/browse/XWIKI-19838
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira
- Email us at Security ML
Payload Generator
The Javascript code below produces 32768 nested group blocks, around the Hello text.
let result = "(((\nHello\n)))";
for (let i = 0; i < 15; ++i) {
result = result.replace("Hello", result);
}
console.log(result);
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2023-26479
xwiki vulnerable to Improper Handling of Exceptional Conditions
Moderate severity GitHub Reviewed Published Mar 1, 2023 in xwiki/xwiki-platform • Updated Mar 3, 2023
Package
maven org.xwiki.platform:xwiki-platform-rendering-parser (Maven)
Affected versions
>= 6.0, < 13.10.10
>= 14.0, < 14.4.6
>= 14.5, < 14.9-rc-1
Patched versions
13.10.10
14.4.6
14.9-rc-1
Impact
Users with write rights can insert well-formed content that is not handled well by the parser. For instance, with xwiki/2.1, inserting a deeply nested group blocks (((( ((( ((( ((( … ))) ))) ))) ))) (see the generator below to produce a large payload) can lead to the parser throwing a StackOverflowError.
As a consequence, some pages becomes unusable, including:
- the user index (if the page containing the faulty content is a user page)
- the page index
Note that on the page, the normal UI is completely missing and it is not possible to open the editor directly to revert the change as the stack overflow is already triggered while getting the title of the document. This means that it is quite difficult to remove this content once inserted.
Patches
This has been patched on XWiki 13.10.10, 14.4.6, and 14.9-rc-1.
Workarounds
A temporary solution to avoid Stack Overflow errors is to increase the memory allocated to the stack by using the -Xss JVM parameter (e.g., -Xss32m). This should allow the parser to pass and to fix the faulty content.
Note that we did not evaluated the consequence on other aspects of the system (e.g., performances), and should be only be used as a temporary solution.
Also, this does not prevent the issue to occur again with another content.
Consequently, it is strongly advised to upgrade to a version where the issue has been patched.
References
- https://jira.xwiki.org/browse/XWIKI-19838
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira
- Email us at Security ML
Payload Generator
The Javascript code below produces 32768 nested group blocks, around the Hello text.
let result = "(((\nHello\n)))"; for (let i = 0; i < 15; ++i) { result = result.replace("Hello", result); } console.log(result);
References
- GHSA-52vf-hvv3-98h7
- https://nvd.nist.gov/vuln/detail/CVE-2023-26479
- xwiki/xwiki-platform@e5b82cd
- https://jira.xwiki.org/browse/XWIKI-19838
Published by the National Vulnerability Database
Mar 2, 2023
Published to the GitHub Advisory Database
Mar 3, 2023
Related news
XWiki Platform is a generic wiki platform. Starting in version 6.0, users with write rights can insert well-formed content that is not handled well by the parser. As a consequence, some pages becomes unusable, including the user index (if the page containing the faulty content is a user page) and the page index. Note that on the page, the normal UI is completely missing and it is not possible to open the editor directly to revert the change as the stack overflow is already triggered while getting the title of the document. This means that it is quite difficult to remove this content once inserted. This has been patched in XWiki 13.10.10, 14.4.6, and 14.9-rc-1. A temporary workaround to avoid Stack Overflow errors is to increase the memory allocated to the stack by using the `-Xss` JVM parameter (e.g., `-Xss32m`). This should allow the parser to pass and to fix the faulty content. The consequences for other aspects of the system (e.g., performance) are unknown, and this workaround shoul...