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Index: gnome-vfs-2.24.2/imported/neon/ne_xml.c
===================================================================
--- gnome-vfs-2.24.2/imported/neon/ne_xml.c (revision 1687)
+++ gnome-vfs-2.24.2/imported/neon/ne_xml.c (revision 1688)
@@ -405,6 +405,28 @@
destroy_element(elm);
}
+#if defined(HAVE_EXPAT) && XML_MAJOR_VERSION > 1
+/* Stop the parser if an entity declaration is hit. */
+static void entity_declaration(void *userData, const XML_Char *entityName,
+ int is_parameter_entity, const XML_Char *value,
+ int value_length, const XML_Char *base,
+ const XML_Char *systemId, const XML_Char *publicId,
+ const XML_Char *notationName)
+{
+ ne_xml_parser *parser = userData;
+
+ NE_DEBUG(NE_DBG_XMLPARSE, "XML: entity declaration [%s]. Failing.\n",
+ entityName);
+
+ XML_StopParser(parser->parser, XML_FALSE);
+}
+#elif defined(HAVE_EXPAT)
+/* A noop default_handler. */
+static void default_handler(void *userData, const XML_Char *s, int len)
+{
+}
+#endif
+
/* Find a namespace definition for 'prefix' in given element, where
* length of prefix is 'pfxlen'. Returns the URI or NULL. */
static const char *resolve_nspace(const struct element *elm,
@@ -459,14 +481,34 @@
XML_SetCharacterDataHandler(p->parser, char_data);
XML_SetUserData(p->parser, (void *) p);
XML_SetXmlDeclHandler(p->parser, decl_handler);
+
+ /* Prevent the "billion laughs" attack against expat by disabling
+ * internal entity expansion. With 2.x, forcibly stop the parser
+ * if an entity is declared - this is safer and a more obvious
+ * failure mode. With older versions, installing a noop
+ * DefaultHandler means that internal entities will be expanded as
+ * the empty string, which is also sufficient to prevent the
+ * attack. */
+#if XML_MAJOR_VERSION > 1
+ XML_SetEntityDeclHandler(p->parser, entity_declaration);
#else
+ XML_SetDefaultHandler(p->parser, default_handler);
+#endif
+
+#else /* HAVE_LIBXML */
p->parser = xmlCreatePushParserCtxt(&sax_handler,
(void *)p, NULL, 0, NULL);
if (p->parser == NULL) {
abort();
}
+#if LIBXML_VERSION < 20602
p->parser->replaceEntities = 1;
+#else
+ /* Enable expansion of entities, and disable network access. */
+ xmlCtxtUseOptions(p->parser, XML_PARSE_NOENT | XML_PARSE_NONET);
#endif
+
+#endif /* HAVE_LIBXML || HAVE_EXPAT */
return p;
}