by Kastro
Paper/Archive/CVE-2021-41773

CVE-2021-41773

Apache Software Foundation Apache HTTP Server — Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

KEV · due 17 Novransomware useEPSS 100%public exploitSSVC actCVSS 9.8
critical.is priorityof 100
99
CVSS 9.8 (NVD)9.8 / 10 × 3029.4In CISA KEV+3030.0EPSS percentile 100.01.000 × 2020.0Exploit: SSVC active+1010.0SSVC exploitation: active+1010.0
Description · from the CVE record

A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. 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 is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

Affected

ProductAffectedFixed inSource
Apache HTTP ServerApache HTTP Server 2.4 2.4.49–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADP7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CISA ADPSSVCExploitation: active · Automatable: yes · Technical impact: total

References

refhttpd.apache.org/security/vulnerabilities_24.htmlreflists.apache.org/thread.html/r6abf5f2ba6f1aa8b1030f95367aaf17660c4e4c78cb2338aee18982f%40%3Cusers.httpd.apache.org%3Ereflists.apache.org/thread.html/r98d704ed4377ed889d40479db79ed1ee2f43b2ebdd79ce84b042df45%40%3Cannounce.apache.org%3Erefopenwall.com/lists/oss-security/2021/10/05/2refopenwall.com/lists/oss-security/2021/10/07/1reflists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.apache.org%3Ereflists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3Erefopenwall.com/lists/oss-security/2021/10/07/6advisorytools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZrefopenwall.com/lists/oss-security/2021/10/08/1reflists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3Erefopenwall.com/lists/oss-security/2021/10/08/2refopenwall.com/lists/oss-security/2021/10/08/3refopenwall.com/lists/oss-security/2021/10/08/4refopenwall.com/lists/oss-security/2021/10/08/6refopenwall.com/lists/oss-security/2021/10/08/5refopenwall.com/lists/oss-security/2021/10/09/1refpacketstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.htmlrefpacketstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.htmlrefopenwall.com/lists/oss-security/2021/10/11/4advisorylists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CCadvisorylists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3refopenwall.com/lists/oss-security/2021/10/15/3refopenwall.com/lists/oss-security/2021/10/16/1reforacle.com/security-alerts/cpujan2022.htmlrefsecurity.netapp.com/advisory/ntap-20211029-0009refpacketstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.htmlrefpacketstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.htmladvisorysecurity.gentoo.org/glsa/202208-20refcisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-41773kevcisa.gov/known-exploited-vulnerabilities-catalog