Denial of Service via WebSocket PING flood

Summary

By default, curl automatically responds to WebSocket PING frames. Because curl lacks an upper bound on memory allocation for unacknowledged frames, a malicious server can exhaust all available memory by flooding curl with rapid, sequential PING messages. A flaw was found in curl. A malicious server can exploit this vulnerability by sending rapid, sequential WebSocket PING messages. Due to a lack of an upper bound on memory allocation for unacknowledged frames, curl can be forced to exhaust all available memory, leading to a denial of service. This Important denial of service vulnerability in curl allows a remote malicious server to exhaust system memory. By default, curl automatically responds to WebSocket PING frames without an upper bound on memory allocation, enabling an attacker to trigger resource exhaustion and cause service unavailability in affected Red Hat products. Red Hat severity: Important — CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-770. No fixing RHSA erratum has published yet; monitor the Red Hat CVE page and patch when it ships. Will not fix / out of support: Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7.