Vulnerability identifier: #VU25020

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-8517

CWE-ID: CWE-119

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 attack.

The vulnerability exists due to a boundary error in the NTLM authentication credentials parser in ext_lm_group_acl. A remote attacker can send a specially crafted HTTP request to the affected proxy server, trigger memory corruption and perform a denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 4.0.1 - 4.9, 3.0 - 3.5.28, 2.7 RC2 - 2.7.STABLE9, 2.4 - 2.4_stable_3, 2.5.6 - 2.5_stable9, 2.3.devel2 - 2.3_stable5, 2.1.patch1 - 2.1_patch2, 2.0.patch1 - 2.0_patch2, 2.2.devel3 - 2.2.stable5, 2.6.stable1 - 2.6.stable6

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External links
http://www.squid-cache.org/Advisories/SQUID-2020_3.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.