An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.
This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 9.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 3 products from squid-cache, from debian, from canonical organizations running these solutions should prioritize assessment and patching.
Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2020-04-15T19:15:12.533
2024-11-21T04:23:02.080
Modified
CVSSv3.1: 9.8 (CRITICAL)
AV:N/AC:L/Au:N/C:P/I:P/A:P
10.0
6.4
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | squid-cache | squid | ≤ 4.7 | Yes |
| Operating System | debian | debian_linux | 9.0 | Yes |
| Operating System | debian | debian_linux | 10.0 | Yes |
| Operating System | canonical | ubuntu_linux | 16.04 | Yes |
| Operating System | canonical | ubuntu_linux | 18.04 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For squid-cache's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.