DIVD-2021-00027 - Apache HTTP 2.4.49 Path Traversal and File Disclosure

Our reference DIVD-2021-00027
Case lead Ralph Horn
Author Diego Klinkhamer
Researcher(s)
CVE(s)
Product Apache HTTP Server
Versions 2.4.49/2.4.50
Recommendation Upgrade to 2.4.51
Patch status Full patched
Status Closed
Last modified 12 Aug 2022 11:21 CEST

Summary

Apache HTTP Server project version 2.4.49 has a vulnerability in their path normalization which allows an attacker to map URLs to files outside the document root by launching a path traversal and file disclosure. The vulnerability can also be bypassed in apache 2.4.50. As there has been evidence of exploitation in the wild we advice to patch with high priority.

What you can do

If you run Apache HTTP server version 2.4.49/2.4.50, downgrade to 2.4.48 or upgrade to 2.4.51.

What we are doing

We are actively scanning for vulnerable machines on the internet.

Timeline

Date Description
29 Sep 2021 CVE-2021-41773 reported by the ASF security team.
04 Oct 2021 CVE-2021-41773 patched and documented
05 Oct 2021 First version of this case file
05 Oct 2021 DIVD is actively scanning for vulnerable servers.
06 Oct 2021 First round of notifications sent about 10269 vulnerable hosts
07 Oct 2021 Apache 2.51 released to mitigate {% cve CVE-2021-41773 %}
26 Oct 2021 Rescanned the internet. Second round of notifications sent about 6945 vulnerable hosts
01 Dec 2021 Based on final scan, 158 vulnerable hosts have been identified. Notifcations sent
01 Dec 2021 Case closed
gantt title DIVD-2021-00027 - Apache HTTP 2.4.49 Path Traversal and File Disclosure dateFormat YYYY-MM-DD axisFormat %e %b %Y section Case DIVD-2021-00027 - Apache HTTP 2.4.49 Path Traversal and File Disclosure (57 days) :2021-10-05, 2021-12-01 section Events CVE-2021-41773 reported by the ASF security team. : milestone, 2021-09-29, 0d CVE-2021-41773 patched and documented : milestone, 2021-10-04, 0d First version of this case file : milestone, 2021-10-05, 0d DIVD is actively scanning for vulnerable servers. : milestone, 2021-10-05, 0d First round of notifications sent about 10269 vulnerable hosts : milestone, 2021-10-06, 0d Apache 2.51 released to mitigate {% cve CVE-2021-41773 %} : milestone, 2021-10-07, 0d Rescanned the internet. Second round of notifications sent about 6945 vulnerable hosts : milestone, 2021-10-26, 0d Based on final scan, 158 vulnerable hosts have been identified. Notifcations sent : milestone, 2021-12-01, 0d Case closed : milestone, 2021-12-01, 0d

Graph showing vulnerable hosts over time

More information