#VU10164 NULL pointer derefenrece in Squid - CVE-2018-1000027

Vulnerability identifier: #VU10164

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

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: 3.0.stable1 - 3.5.27, 4.0 - 4.0.22

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External links
https://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.