diff --git a/base/file_util.h b/base/file_util.h
index 47254ab..3d07229 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -316,7 +316,7 @@
 
 // Creates a directory, as well as creating any parent directories, if they
 // don't exist. Returns 'true' on successful creation, or if the directory
-// already exists.
+// already exists.  The directory is only readable by the current user.
 bool CreateDirectory(const FilePath& full_path);
 // Deprecated temporary compatibility function.
 bool CreateDirectory(const std::wstring& full_path);
diff --git a/base/file_util_posix.cc b/base/file_util_posix.cc
index 06f3c1a..ae296ca 100644
--- a/base/file_util_posix.cc
+++ b/base/file_util_posix.cc
@@ -214,8 +214,7 @@
         }
 
         // Try creating the target dir, continuing on it if it exists already.
-        // Rely on the user's umask to produce correct permissions.
-        if (mkdir(target_path.value().c_str(), 0777) != 0) {
+        if (mkdir(target_path.value().c_str(), 0700) != 0) {
           if (errno != EEXIST)
             error = errno;
         }
@@ -425,7 +424,7 @@
   for (std::vector<FilePath>::reverse_iterator i = subpaths.rbegin();
        i != subpaths.rend(); ++i) {
     if (!DirectoryExists(*i)) {
-      if (mkdir(i->value().c_str(), 0777) != 0)
+      if (mkdir(i->value().c_str(), 0700) != 0)
         return false;
     }
   }