AUGUST 4, 2026
Live Feed
Back to database
Case File

CVE-2021-33620

MEDIUM · CVSS 6.5 EPSS 79.58% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-05-28 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 6.5. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 79.6% probability of exploitation in the next 30 days. It may be remotely exploitable. It may lead to a denial-of-service condition.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-33620
Severity
MEDIUM
CVSS
6.5
EPSS
79.58%

Original NVD Description

Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.

Related CVEs

Other vulnerabilities affecting the same vendor(s)