Squid 3.x < 3.5.6 Multiple Vulnerabilities

high Nessus Network Monitor Plugin ID 8951


The remote proxy server is affected by multiple vulnerabilities.


Versions of Squid 3.x prior to 3.5.6 are potentially affected by by the following vulnerabilities :

- An authentication bypass vulnerability exists due to a flaw in file 'tunnel.cc', which is triggered whenever cache peer CONNECT responses are blindly forwarded in a hierarchy of two or more proxies, resulting in unrestricted access to a back-end proxy through its gateway proxy. A remote, unauthenticated attacker, using a specially crafted request, can exploit this vulnerability to bypass authentication or gain access to protected resources. This issue occurs in configurations with cache_peer enabled, and exploitation would require that the two proxies have differing levels of security. (CVE-2015-5400)
- A flaw in 'ssl/support.cc' that is triggered during the handling of repeated client-initiated TLS renegotation messages. This may allow a remote attacker to cause a denial of service.


Either upgrade to Squid version 3.5.6 or later, or apply the vendor-supplied patch.

See Also




Plugin Details

Severity: High

ID: 8951

Family: Web Servers

Published: 10/13/2015

Updated: 3/6/2019

Nessus ID: 84674

Risk Information


Risk Factor: High

Base Score: 7.1

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C


Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*

Patch Publication Date: 7/3/2015

Vulnerability Publication Date: 7/6/2015

Reference Information

CVE: CVE-2015-5400

BID: 75553