Apache HTTP Server-Side Request Forgery (SSRF)

Critical Threat Advisory: This vulnerability is documented in active Ransomware campaigns. Immediate remediation required.

Technical Severity

CVSS v3.1 Metrics

CRITICAL

9 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation Likelihood

EPSS Prediction

100.00 %

Predictive Probability

Percentile Rank

100.0 th

Documented as more likely to be exploited than 100.0% of known CVEs.

Detection Date

Dec 01, 2021

Remediation Due

Dec 15, 2021

CISA Catalog Active

Threat Analysis

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.

Remediation Directive

Apply updates per vendor instructions.

External Intelligence

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2021-40438