Amazon Linux 2023: CVE-2023-45288: Medium priority package update for amazon-cloudwatch-agent (Multiple Advisories)

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.
A vulnerability was discovered with the implementation of the HTTP/2 protocol in the Go programming language. There were insufficient limitations on the amount of CONTINUATION frames sent within a single stream. An attacker could potentially exploit this to cause a Denial of Service (DoS) attack.