Vulnerabilities > CVE-2023-36470 - Injection vulnerability in Xwiki
Summary
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. By either creating a new or editing an existing document with an icon set, an attacker can inject XWiki syntax and Velocity code that is executed with programming rights and thus allows remote code execution. There are different attack vectors, the simplest is the Velocity code in the icon set's HTML or XWiki syntax definition. The [icon picker](https://extensions.xwiki.org/xwiki/bin/view/Extension/Icon%20Theme%20Application#HIconPicker) can be used to trigger the rendering of any icon set. The XWiki syntax variant of the icon set is also used without any escaping in some documents, allowing to inject XWiki syntax including script macros into a document that might have programming right, for this the currently used icon theme needs to be edited. Further, the HTML output of the icon set is output as JSON in the icon picker and this JSON is interpreted as XWiki syntax, allowing again the injection of script macros into a document with programming right and thus allowing remote code execution. This impacts the confidentiality, integrity and availability of the whole XWiki instance. This issue has been patched in XWiki 14.10.6 and 15.1. Icon themes now require script right and the code in the icon theme is executed within the context of the icon theme, preventing any rights escalation. A macro for displaying icons has been introduced to avoid injecting the raw wiki syntax of an icon set into another document. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Server Side Include (SSI) Injection An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
- Cross Site Scripting through Log Files An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
- Subverting Environment Variable Values The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
References
- https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-fm68-j7ww-h9xf
- https://github.com/xwiki/xwiki-platform/commit/46b542854978e9caa687a5c2b8817b8b17877d94
- https://github.com/xwiki/xwiki-platform/commit/79418dd92ca11941b46987ef881bf50424898ff4
- https://jira.xwiki.org/browse/XWIKI-20524
- https://github.com/xwiki/xwiki-platform/commit/b0cdfd893912baaa053d106a92e39fa1858843c7