CVE-2023-46728

2023-11-0714:37:53

redhat.com

access.redhat.com

squid

caching proxy

gopher

dos

attack

vulnerability

mitigation

access list

configuration

acl directives

7.5 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

0.004 Low

EPSS

Percentile

72.8%

JSON

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a NULL pointer dereference bug Squid is vulnerable to a Denial of Service attack against Squid’s Gopher gateway. The gopher protocol is always available and enabled in Squid. This issue may lead to a remote denial of service via gopher URL requests.

Mitigation

To mitigate this issue, create an access list configuration to reject all gopher URL requests:

Set ACL directives in your squid.conf file (or equivalent) as follows:
acl gopher proto gopher
http_access deny gopher

Important: This sequence must be placed above any lines starting with "http_access allow" in your configuration.
Observation: Some loss of performance may occur with this configuration.