{"id":"USN-5090-3","aliases":[],"status":"published","title":"apache2 regression","description":"USN-5090-1 fixed vulnerabilities in Apache HTTP Server. One of the upstream\nfixes introduced a regression in UDS URIs. This update fixes the problem.\n\nOriginal advisory details:\n\n James Kettle discovered that the Apache HTTP Server HTTP/2 module\n incorrectly handled certain crafted methods. A remote attacker could\n possibly use this issue to perform request splitting or cache poisoning\n attacks. (CVE-2021-33193)\n \n It was discovered that the Apache HTTP Server incorrectly handled certain\n malformed requests. A remote attacker could possibly use this issue to\n cause the server to crash, resulting in a denial of service.\n (CVE-2021-34798)\n \n Li Zhi Xin discovered that the Apache mod_proxy_uwsgi module incorrectly\n handled certain request uri-paths. A remote attacker could possibly use\n this issue to cause the server to crash, resulting in a denial of service.\n This issue only affected Ubuntu 20.04 LTS and Ubuntu 21.04.\n (CVE-2021-36160)\n \n It was discovered that the Apache HTTP Server incorrectly handled escaping\n quotes. If the server was configured with third-party modules, a remote\n attacker could use this issue to cause the server to crash, resulting in a\n denial of service, or possibly execute arbitrary code. (CVE-2021-39275)\n \n It was discovered that the Apache mod_proxy module incorrectly handled\n certain request uri-paths. A remote attacker could possibly use this issue\n to cause the server to forward requests to arbitrary origin servers.\n (CVE-2021-40438)","facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2021-09-28T13:28:37Z","modified":"2026-04-22T10:18:18Z","fixes":[{"ecosystem":"Ubuntu:18.04:LTS","package":"apache2","fixed_in":["2.4.29-1ubuntu4.18"],"sources":["osv"]},{"ecosystem":"Ubuntu:20.04:LTS","package":"apache2","fixed_in":["2.4.41-4ubuntu3.6"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"apache2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.29-1ubuntu4.18"}]}],"versions":["2.4.27-2ubuntu3","2.4.29-1ubuntu1","2.4.29-1ubuntu2","2.4.29-1ubuntu3","2.4.29-1ubuntu4","2.4.29-1ubuntu4.1","2.4.29-1ubuntu4.2","2.4.29-1ubuntu4.3","2.4.29-1ubuntu4.4","2.4.29-1ubuntu4.5","2.4.29-1ubuntu4.6","2.4.29-1ubuntu4.7","2.4.29-1ubuntu4.8","2.4.29-1ubuntu4.10","2.4.29-1ubuntu4.11","2.4.29-1ubuntu4.12","2.4.29-1ubuntu4.13","2.4.29-1ubuntu4.14","2.4.29-1ubuntu4.16","2.4.29-1ubuntu4.17"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"apache2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.41-4ubuntu3.6"}]}],"versions":["2.4.41-1ubuntu1","2.4.41-4ubuntu1","2.4.41-4ubuntu2","2.4.41-4ubuntu3","2.4.41-4ubuntu3.1","2.4.41-4ubuntu3.3","2.4.41-4ubuntu3.4","2.4.41-4ubuntu3.5"]}],"references":[{"url":"https://ubuntu.com/security/notices/USN-5090-3","tags":["advisory"]},{"url":"https://launchpad.net/bugs/1945311","tags":["report"]}],"sources":{"osv":[{"id":"USN-5090-3","title":"apache2 regression","description":"USN-5090-1 fixed vulnerabilities in Apache HTTP Server. One of the upstream\nfixes introduced a regression in UDS URIs. This update fixes the problem.\n\nOriginal advisory details:\n\n James Kettle discovered that the Apache HTTP Server HTTP/2 module\n incorrectly handled certain crafted methods. A remote attacker could\n possibly use this issue to perform request splitting or cache poisoning\n attacks. (CVE-2021-33193)\n \n It was discovered that the Apache HTTP Server incorrectly handled certain\n malformed requests. A remote attacker could possibly use this issue to\n cause the server to crash, resulting in a denial of service.\n (CVE-2021-34798)\n \n Li Zhi Xin discovered that the Apache mod_proxy_uwsgi module incorrectly\n handled certain request uri-paths. A remote attacker could possibly use\n this issue to cause the server to crash, resulting in a denial of service.\n This issue only affected Ubuntu 20.04 LTS and Ubuntu 21.04.\n (CVE-2021-36160)\n \n It was discovered that the Apache HTTP Server incorrectly handled escaping\n quotes. If the server was configured with third-party modules, a remote\n attacker could use this issue to cause the server to crash, resulting in a\n denial of service, or possibly execute arbitrary code. (CVE-2021-39275)\n \n It was discovered that the Apache mod_proxy module incorrectly handled\n certain request uri-paths. A remote attacker could possibly use this issue\n to cause the server to forward requests to arbitrary origin servers.\n (CVE-2021-40438)\n","status":"published","published":"2021-09-28T13:28:37Z","modified":"2026-04-22T10:18:18.969795Z","updated_at":"2026-11-02T16:58:15.683829Z"}]}}