CVE-2020-15811

Published Sep 2, 2020

Last updated 9 months ago

Overview

Description
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.
Source
cve@mitre.org
NVD status
Analyzed

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
3.6
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Severity
MEDIUM

CVSS 2.0

Type
Primary
Base score
4
Impact score
2.9
Exploitability score
8
Vector string
AV:N/AC:L/Au:S/C:N/I:P/A:N

Weaknesses

nvd@nist.gov
CWE-697

Social media

Hype score
Not currently trending

Configurations