An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.3, 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 limited integrity, for affected systems. Impacting 4 products from squid-cache, from canonical, from debian and 1 other, organizations running these solutions should prioritize assessment and patching.
First disclosed in 2019, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.
2019-11-26T17:15:12.983
2024-11-21T04:33:30.973
Modified
CVSSv3.1: 5.3 (MEDIUM)
AV:N/AC:L/Au:N/C:N/I:P/A:N
10.0
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | squid-cache | squid | ≤ 3.5.28 | Yes |
| Application | squid-cache | squid | ≤ 4.8 | Yes |
| Operating System | canonical | ubuntu_linux | 16.04 | Yes |
| Operating System | canonical | ubuntu_linux | 18.04 | Yes |
| Operating System | canonical | ubuntu_linux | 19.04 | Yes |
| Operating System | canonical | ubuntu_linux | 19.10 | Yes |
| Operating System | debian | debian_linux | 8.0 | Yes |
| Operating System | fedoraproject | fedora | 30 | Yes |
| Operating System | fedoraproject | fedora | 31 | 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.