USN-6885-3: Apache HTTP Server vulnerabilities

USN-6885-1 fixed several vulnerabilities in Apache. This update provides the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. Original advisory details: Orange Tsai discovered that the Apache HTTP Server modrewrite module incorrectly handled certain substitutions. A remote attacker could possibly use this issue to execute scripts in directories not directly reachable by any URL, or cause a denial of service. Some environments may require using the new UnsafeAllow3F flag to handle unsafe substitutions. (CVE-2024-38474, CVE-2024-38475) Orange Tsai discovered that the Apache HTTP Server incorrectly handled certain response headers. A remote attacker could possibly use this issue to obtain sensitive information, execute local scripts, or perform SSRF attacks. (CVE-2024-38476) Orange Tsai discovered that the Apache HTTP Server modproxy module incorrectly handled certain requests. A remote attacker could possibly use this issue to cause the server to crash, resulting in a denial of service. (CVE-2024-38477)