All vulnerabilities
CVE-2021-40438

Apache HTTP Server-Side Request Forgery (SSRF)

Apache Apache
Open in ThreatlineRecord JSON
CVSS
9.0Critical
ExploitationExploited in the wildAdded to KEV 1 Dec 2021. Known ransomware useCISA KEV
Exploit odds (EPSS)>99.9%Chance of exploitation activity in the next 30 days, higher than 99.9% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Federal deadline15 Dec 2021Remediation due date for US federal agenciesCISA KEV
CISA required actionApply updates per vendor instructions. CISA KEV

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

  1. 16 Sep 2021, 14:40 UTCPublishedCVE List
  2. 1 Dec 2021Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Scanner templateApache <= 2.4.48 Mod_Proxy - Server-Side Request ForgeryNuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

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.

Text from CVE List

Affected versions 1

  • Apache HTTP Serveraffected: Apache HTTP Server 2.4 through 2.4.48CVE List

References 21