Description

An integer overflow vulnerability in the HTTP chunked transfer encoding parser in tinyproxy up to and including version 1.11.3 allows an unauthenticated remote attacker to cause a denial of service (DoS). The issue occurs because chunk size values are parsed using strtol() without properly validating overflow conditions (e.g., errno == ERANGE). A crafted chunk size such as 0x7fffffffffffffff (LONG_MAX) bypasses the existing validation check (chunklen < 0), leading to a signed integer overflow during arithmetic operations (chunklen + 2). This results in incorrect size calculations, causing the proxy to attempt reading an extremely large amount of request-body data and holding worker connections open indefinitely. An attacker can exploit this behavior to exhaust all available worker slots, preventing new connections from being accepted and causing complete service unavailability. Upstream addressed this issue in commit bb7edc4; however, the latest stable release (1.11.3) remains affected at the time of publication.

INFO

Published Date :

2026-03-30T07:05:23.295Z

Last Modified :

2026-03-30T15:02:33.584Z

Source :

TuranSec
AFFECTED PRODUCTS

The following products are affected by CVE-2026-3945 vulnerability.

Vendors Products
Tinyproxy
  • Tinyproxy

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
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Privileges Required
User Interaction
VS Confidentiality
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SS Confidentiality
SS Integrity
SS Availability
Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
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Integrity Impact
Availability Impact
Detailed values of each vector for above chart.
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact