Skip to main content

CVE-2016-4553

8.6
HIGHCVSS v3.1 Base Score
82.84%
HIGH RiskEPSS (99th percentile)

client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when absolute-URI is provided, which allows remote attackers to conduct cache-poisoning attacks via an HTTP request.

Published: 5/10/2016
Modified: 5/6/2026
Back to CVE Lookup

Vulnerability Summary

CVSS v3 Score

8.6HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

CVSS v2 Score

5

AV:N/AC:L/Au:N/C:N/I:P/A:N

EPSS Score (Exploitation Probability)

82.84%HIGH Exploitation Risk
99th percentile

This vulnerability has a 82.84% probability of being exploited in the next 30 days, ranking higher than 99% of all scored CVEs.

CWE Classification

Related Vulnerabilities

Same Weakness Type(CWE-345)

CVE-2025-66570CRITICAL 10

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability allows attacker-controlled HTTP headers to influence server-visible metadata, logging, and authorization decisions. An attacker can inject headers named REMOTE_ADDR, REMOTE_PORT, LOCAL_ADDR, LOCAL_PORT that are parsed into the request header multimap via read_headers() in httplib.h (headers.emplace), then the server later appends its own internal metadata using the same header names in Server::process_request without erasing duplicates. Because Request::get_header_value returns the first entry for a header key (id == 0) and the client-supplied headers are parsed before server-inserted headers, downstream code that uses these header names may inadvertently use attacker-controlled values. Affected files/locations: cpp-httplib/httplib.h (read_headers, Server::process_request, Request::get_header_value, get_header_value_u64) and cpp-httplib/docker/main.cc (get_client_ip, nginx_access_logger, nginx_error_logger). Attack surface: attacker-controlled HTTP headers in incoming requests flow into the Request.headers multimap and into logging code that reads forwarded headers, enabling IP spoofing, log poisoning, and authorization bypass via header shadowing. This vulnerability is fixed in 0.27.0.

12/5/2025
CVE-2025-66255CRITICAL 9.8

Unauthenticated Arbitrary File Upload (upgrade_contents.php) in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter versions 30, 50, 100, 300, 500, 1000, 2000, 3000, 3500, 6000, 7000 allows an attacker to perform Missing signature validation allows uploading malicious firmware packages.  The firmware upgrade endpoint in `upgrade_contents.php` accepts arbitrary file uploads without validating file headers, cryptographic signatures, or enforcing .tgz format requirements, allowing malicious firmware injection. This endpoint also subsequently provides ways for arbitrary file uploads and subsequent remote code execution

11/26/2025
CVE-2025-49199HIGH 8.8

The backup ZIPs are not signed by the application, leading to the possibility that an attacker can download a backup ZIP, modify and re-upload it. This allows the attacker to disrupt the application by configuring the services in a way that they are unable to run, making the application unusable. They can redirect traffic that is meant to be internal to their own hosted services and gathering information.

6/12/2025
CVE-2025-48865CRITICAL 9.1

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.

5/30/2025
CVE-2025-1945CRITICAL 9.8

picklescan before 0.0.23 fails to detect malicious pickle files inside PyTorch model archives when certain ZIP file flag bits are modified. By flipping specific bits in the ZIP file headers, an attacker can embed malicious pickle files that remain undetected by PickleScan while still being successfully loaded by PyTorch's torch.load(). This can lead to arbitrary code execution when loading a compromised model.

3/10/2025

Similar SeverityHIGH