CVE-2015-5309
Integer overflow in the terminal emulator in PuTTY before 0.66 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via an ECH (erase characters) escape sequence with a large parameter value, which triggers a buffer underflow.
Date published : 2015-12-07
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-ech-overflow.html