I am using the default config while adding the specific directory with nginx installed on my ubuntu 12.04 machine.
server {
#listen 80; ## listen
Symptom:
Could not upload images to WordPress Media Library.
Cause:
(CentOS) yum update
Error:
2014/10/22 18:08:50 [crit] 23286#0: *5332 open() "/var/lib/nginx/tmp/client_body/0000000003" failed (13: Permission denied), client: 1.2.3.4, server: _, request: "POST /wp-admin/media-new.php HTTP/1.1", host: "example.com", referrer: "http://example/wp-admin/media-new.php"
Solution:
chown -R www-data:www-data /var/lib/nginx