Squid < 3.5.18 Host Header Handling Same-Origin Protection / Content Filtering Bypass (SQUID-2016:8)

Medium Nessus Plugin ID 108809

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VPR Score: 4.4


The remote proxy server is potentially affected by a same-origin filtering bypass vulnerability.


According to its banner, the version of Squid running on the remote host is prior to 3.5.18. It is, therefore, potentially affected by a Host header same-origin filtering bypass vulnerability. A remote attacker could exploit this issue to poison the cache by forcing a Host header value past same-origin security protections to cause Squid to contact the wrong origin server.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Furthermore, the patch released to address this issue does not update the version given in the banner. If the patch has been applied properly, and the service has been restarted, then consider this to be a false positive.


Upgrade to Squid version 3.5.18 or later. Alternatively, apply the vendor-supplied patch.

See Also


Plugin Details

Severity: Medium

ID: 108809

File Name: squid_3_5_18.nasl

Version: 1.4

Type: remote

Family: Firewalls

Published: 2018/04/03

Updated: 2018/12/17

Dependencies: 49692

Configuration: Enable paranoid mode

Risk Information

Risk Factor: Medium

VPR Score: 4.4

CVSS Score Source: CVE-2016-4554

CVSS v2.0

Base Score: 5

Temporal Score: 3.7

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

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

CVSS v3.0

Base Score: 8.6

Temporal Score: 7.5

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

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

Vulnerability Information

CPE: cpe:/a:squid-cache:squid

Required KB Items: installed_sw/Squid, Settings/ParanoidReport

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2016/05/06

Vulnerability Publication Date: 2016/05/06

Reference Information

CVE: CVE-2016-4554