Format string vulnerability in the _msg function in error.c in socat 1.4.0.3 and earlier, when used as an HTTP proxy client and run with the -ly option, allows remote attackers or local users to execute arbitrary code via format string specifiers in a syslog message.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17822
http://www.gentoo.org/security/en/glsa/glsa-200410-26.xml