{"schemaVersion":3,"id":"USN-5090-4","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"apache2 regression\n\nUSN-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)","dates":{"published":"2021-09-28T15:05:47.000Z","modified":"2026-06-25T13:30:48.373Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":null,"severity":"unknown","version":null,"versionLabel":null,"source":null,"vector":null,"computed":false,"selection":"none"},"metrics":[]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"ubuntu","product":"apache2","name":"apache2","label":"apache2","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/apache2","purlType":"deb","versions":[{"text":"< 2.4.18-2ubuntu3.17+esm3","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2.4.18-2ubuntu3.17+esm3","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-5090-4","label":"ubuntu.com/security/notices/USN-5090-4","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://launchpad.net/bugs/1945311","label":"launchpad.net/bugs/1945311","hostname":"launchpad.net","tags":["REPORT"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2021-09-28T15:05:47.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-06-25T13:30:48.373Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":0,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T22:03:03.119Z","stale":false,"partial":false}}