Vulnerability identifier: #VU10164

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-1000027

CWE-ID: CWE-476

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 a denial of service (DoS) attack.

The vulnerability exists due to incorrect pointer handling when processing ESI responses or downloading intermediate CA certificates. A remote attacker can supply a specially crafted response to the vulnerable server and trigger application crash.

Mitigation
Update to version 4.0.23.

Vulnerable software versions

Squid: 4.0 - 4.0.22, 3.0.stable1 - 3.5.27

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External links
http://www.squid-cache.org/Advisories/SQUID-2018_2.txt

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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.