{"basis":"claimed","id":"CVE-2021-42013","name":"Apache HTTP Server Path Traversal Vulnerability","vendorProject":"Apache","product":"HTTP Server","publishedAt":"2021-10-07","cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1"},"exploited":{"kevAdded":"2021-11-03","dueDate":"2021-11-17","ransomware":true},"epss":{"score":0.99964,"percentile":0.99976,"date":"2026-11-02"},"coverage":{"cloudflare":{"status":"no_history","firstOn":null,"daysToRule":null},"aws":{"status":"none","firstOn":null,"daysToRule":null},"azure":{"status":"none","firstOn":null,"daysToRule":null},"google":{"status":"no_history","firstOn":null,"daysToRule":null},"fastly":{"status":"no_history","firstOn":null,"daysToRule":null},"f5":{"status":"rule","firstOn":"2024-03-12","daysToRule":null},"akamai":{"status":"no_source","firstOn":null,"daysToRule":null},"crs":{"status":"no_history","firstOn":null,"daysToRule":null}},"title":"Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)","description":"It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration \"require all denied\", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue only affects Apache 2.4.49 and Apache 2.4.50 and not earlier versions.","cwes":["CWE-22"],"vendors":[{"vendor":"cloudflare","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"aws","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"azure","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"google","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"fastly","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"f5","status":"rule","basis":"claimed","firstOn":"2024-03-12","firstIsNew":false,"daysToRule":null,"daysAtMost":887,"freePlan":false,"claims":[{"id":"ef0b8cca704011ab01efa2d56000c18902dbd2d80095ff32b06a5629dd552eaf","cve_id":"CVE-2021-42013","vendor":"f5","product":"Attack signatures","rule_id":"200007043","rule_name":"Directory Traversal attempt \"../\" (URI) (%%32%65%%32%65)","change":"updated","default_action":null,"published_on":"2024-03-12","source_url":"https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog","source_title":"F5 Distributed Cloud attack signatures changelog","excerpt":"Updated: signature 200007043 \"Directory Traversal attempt \"../\" (URI) (%%32%65%%32%65)\" (Path Traversal, risk High), systems: Apache. References: CVE-2021-42013, CVE-2021-41773.","first_seen_at":"2026-11-02T21:00:27.754Z"}]},{"vendor":"akamai","status":"no_source","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"crs","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]}],"updatedAt":"2026-11-03T03:17:42.054Z","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","ssvc":{"exploitation":"active","automatable":"yes","technicalImpact":"total"},"measured":[{"engineId":"owasp-crs","engineName":"OWASP Core Rule Set","engineVersion":"4.25.0","runtime":"Coraza v3.8.1","config":"paranoia level 1, anomaly threshold 5, default CRS settings","ranAt":"2026-11-02T13:02:57.000Z","verdict":"error","templateId":"CVE-2021-42013","templatePath":"http/cves/2021/CVE-2021-42013.yaml","requests":3,"blockedRequests":0,"rules":[],"note":"3 request(s) errored","requestDetail":[{"method":"GET","path":"/icons/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32…","status":400,"blocked":false,"rules":[]},{"method":"GET","path":"/icons/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/e…","status":400,"blocked":false,"rules":[]},{"method":"POST","path":"/cgi-bin/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%…","status":400,"blocked":false,"rules":[]}]},{"engineId":"owasp-crs","engineName":"OWASP Core Rule Set","engineVersion":"4.25.0","runtime":"Coraza v3.8.1","config":"paranoia level 2, anomaly threshold 5, default CRS settings","ranAt":"2026-11-02T13:03:28.000Z","verdict":"error","templateId":"CVE-2021-42013","templatePath":"http/cves/2021/CVE-2021-42013.yaml","requests":3,"blockedRequests":0,"rules":[],"note":"3 request(s) errored","requestDetail":[{"method":"GET","path":"/icons/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32…","status":400,"blocked":false,"rules":[]},{"method":"GET","path":"/icons/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/e…","status":400,"blocked":false,"rules":[]},{"method":"POST","path":"/cgi-bin/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%32%65%%32%65/%%…","status":400,"blocked":false,"rules":[]}]}],"social":{"total":0,"first_seen":null,"daily":[{"day":"2026-10-21","posts":0},{"day":"2026-10-22","posts":0},{"day":"2026-10-23","posts":0},{"day":"2026-10-24","posts":0},{"day":"2026-10-25","posts":0},{"day":"2026-10-26","posts":0},{"day":"2026-10-27","posts":0},{"day":"2026-10-28","posts":0},{"day":"2026-10-29","posts":0},{"day":"2026-10-30","posts":0},{"day":"2026-10-31","posts":0},{"day":"2026-11-01","posts":0},{"day":"2026-11-02","posts":0},{"day":"2026-11-03","posts":0}],"top_posts":[],"exploit_repositories":[]}}