svn commit: r428976 - head/security/vuxml

Tue Dec 20 03:13:21 UTC 2016

Author: junovitch
Date: Tue Dec 20 03:13:20 2016
New Revision: 428976
URL: https://svnweb.freebsd.org/changeset/ports/428976

Log:
  Document Xen Security Advisory (XSA 204)
  
  Reported by:	royger
  Security:	CVE-2016-10013
  Security:	https://vuxml.FreeBSD.org/freebsd/942433db-c661-11e6-ae1b-002590263bf5.html

Modified:
  head/security/vuxml/vuln.xml

Modified: head/security/vuxml/vuln.xml
==============================================================================

--- head/security/vuxml/vuln.xml	Tue Dec 20 02:30:58 2016	(r428975)
+++ head/security/vuxml/vuln.xml	Tue Dec 20 03:13:20 2016	(r428976)
@@ -58,6 +58,40 @@ Notes:
   * Do not forget port variants (linux-f10-libxml2, libxml2, etc.)
 -->
 <vuxml xmlns="http://www.vuxml.org/apps/vuxml-1">
+  <vuln vid="942433db-c661-11e6-ae1b-002590263bf5">
+    <topic>xen-kernel -- x86: Mishandling of SYSCALL singlestep during emulation</topic>
+    <affects>
+      <package>
+	<name>xen-kernel</name>
+	<range><lt>4.7.1_2</lt></range>
+      </package>
+    </affects>
+    <description>
+      <body xmlns="http://www.w3.org/1999/xhtml">
+	<p>The Xen Project reports:</p>
+	<blockquote cite="http://xenbits.xen.org/xsa/advisory-204.html">
+	  <p>The typical behaviour of singlestepping exceptions is determined at
+	    the start of the instruction, with a #DB trap being raised at the
+	    end of the instruction. SYSCALL (and SYSRET, although we don't
+	    implement it) behave differently because the typical behaviour
+	    allows userspace to escalate its privilege. (This difference in
+	    behaviour seems to be undocumented.) Xen wrongly raised the
+	    exception based on the flags at the start of the instruction.</p>
+	  <p>Guest userspace which can invoke the instruction emulator can use
+	    this flaw to escalate its privilege to that of the guest kernel.</p>
+	</blockquote>
+      </body>
+    </description>
+    <references>
+      <cvename>CVE-2016-10013</cvename>
+      <url>http://xenbits.xen.org/xsa/advisory-204.html</url>
+    </references>
+    <dates>
+      <discovery>2016-12-19</discovery>
+      <entry>2016-12-20</entry>
+    </dates>
+  </vuln>
+
   <vuln vid="e47ab5db-c333-11e6-ae1b-002590263bf5">
     <topic>atheme-services -- multiple vulnerabilities</topic>
     <affects>
