Format string vulnerability in the print_proxies function in bin/proxy.c in libproxy 0.3.1 might allow context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via format string specifiers in a proxy name, as demonstrated using the http_proxy environment variable or a PAC file.

Heap-based buffer overflow in the px_pac_reload function in lib/pac.c in libproxy 0.2.x and 0.3.x allows remote servers to have an unspecified impact via a crafted Content-Length size in an HTTP response header for a proxy.pac file request, a different vulnerability than CVE-2012-4504.