The host-services component in Symantec pcAnywhere 12.5.x through 12.5.3, and IT Management Suite pcAnywhere Solution 7.0 (aka 12.5.x) and 7.1 (aka 12.6.x), does not properly filter login and authentication data, which allows remote attackers to execute arbitrary code via a crafted session on TCP port 5631.
https://www.exploit-db.com/exploits/38599/
http://www.zerodayinitiative.com/advisories/ZDI-12-018/
http://www.securityfocus.com/bid/51592