CVE-2017-5390

CVE-2017-5390 describes a critical privilege escalation vulnerability in the JSON viewer component of Developer Tools within Mozilla Firefox, Firefox ESR, and Thunderbird. It affects versions prior to Firefox 51, Firefox ESR 45.7, and Thunderbird 45.7. The vulnerability stems from insecure communication methods used for handling JSON and HTTP header data. With a CVSS score of 9.8 (CRITICAL), this vulnerability is easily exploitable over the network with low attack complexity, potentially leading to complete compromise of confidentiality, integrity, and availability. Despite its high severity, there is no evidence of active exploitation, nor are there publicly available exploits in Metasploit or ExploitDB. While not actively exploited, the vulnerability has garnered significant community discussion, indicating awareness among security researchers. However, it has received no media coverage, which is typical for the vast majority of CVEs.