December 1, 2021 · Applied Cybernetics Group
CVE-2021-40438 — Apache Apache
Apache HTTP Server-Side Request Forgery (SSRF)
- Added to KEV
2021-12-01- Federal due date
2021-12-15- Vendor
- Apache
- Product
- Apache
- EPSS
- 100.0th percentile (score 0.944, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2021-40438
CISA short description
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
Required action
Apply updates per vendor instructions.