Every exploited vulnerability / Apache
CVE-2021-41773 in Apache HTTP Server: known exploited
Generated from its entry in CISA's catalogue of known exploited vulnerabilities as of 3 November 2026.
Attackers are exploiting CVE-2021-41773 in Apache HTTP Server. CISA has listed it as known exploited since 3 November 2021.
Ransomware groups have used this vulnerability.
| Product | Apache HTTP Server |
|---|---|
| Known exploited since | 3 November 2021 |
| Ransomware use | Recorded |
| EU vulnerability database | EUVD-2021-28781 |
| Sources | NVD · CISA KEV |
What it means
Attackers have used this vulnerability in real attacks. An unpatched Apache HTTP Server that can be reached from the internet is exposed to them.
What to do
- Apply the vendor's fix to every system running Apache HTTP Server, starting with those reachable from the internet. Take a system off the internet until it can be fixed.
- Check the system for signs that it was reached before the fix.
How Vardion finds it
Wherever a scan or your imported scanner results find CVE-2021-41773, Vardion names the systems affected and puts the fix at the top of the list.