CVE-2017-20201

CVE-2017-20201 describes a supply chain compromise affecting CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 (32-bit builds). Malicious code was embedded, diverting execution to a custom loader that deployed an in-memory payload for data collection and exfiltration to hard-coded or DGA C2 servers. This critical vulnerability (CVSS 9.3) has a network attack vector and low attack complexity, allowing unauthenticated attackers to achieve high confidentiality and integrity impacts through remote data collection and stealthy in-memory execution. While not listed on the KEV catalog, the vulnerability was actively exploited in the wild as a supply chain attack. There are no public Metasploit, Nuclei, or ExploitDB modules, and it has received minimal community discussion or media coverage.