#VU27677 Improper Neutralization of Special Elements in Output Used by a Downstream Component in Squid - CVE-2019-18860

Vulnerability identifier: #VU27677

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-18860

CWE-ID: CWE-74

Exploitation vector: Network

Exploit availability: No

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 cache poisoning attack.

The vulnerability exists due to improper input validation of HTML code within the hostname parameter in cachemgr.cgi. A remote attacker can send a specially crated HTTP request and poison the cache.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 4.0 - 4.8

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External links
https://github.com/squid-cache/squid/pull/504
https://github.com/squid-cache/squid/pull/505

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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.