CVE-2013-4852

CVE-2013-4852 describes an integer overflow vulnerability in PuTTY 0.62 and earlier, WinSCP before 5.1.6, and other PuTTY-based applications. This flaw allows a malicious SSH server to trigger a heap-based buffer overflow by sending a negative size value in an RSA key signature during the SSH handshake. The vulnerability has a CVSS score of 6.8, indicating a medium severity with network access, medium attack complexity, and potential for partial confidentiality, integrity, and availability impact (crash and possible arbitrary code execution). There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.