#VU15896 Cross-site scripting in Squid


Published: 2020-03-18

Vulnerability identifier: #VU15896

Vulnerability risk: Low

CVSSv3.1: 4.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-19131

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Squid
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Squid-cache.org

Description

The vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data when processing a specially crafted X.509 certificate during HTTP(S) error page generation for certificate errors. A remote attacker can trick the victim to follow a specially specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Squid: 4.0.1 - 4.3


External links
http://www.squid-cache.org/Advisories/SQUID-2018_4.txt
http://www.squid-cache.org/Versions/v5/changesets/squid-5-6feeb15ff312f3e145763adf8d234ed6a0b3f11d.patch
http://github.com/squid-cache/squid/pull/306


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.


Latest bulletins with this vulnerability