Vulnerability identifier: #VU53599

Vulnerability risk: Medium

CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2021-31807

CWE-ID: CWE-399

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 a denial of service (DoS) attack.

The vulnerability exists due to improper management of memory within the application when processing HTTP Range header. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 5.0 - 5.0.5, 4.0 - 4.14

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External links
http://security.gentoo.org/glsa/202105-14
http://github.com/squid-cache/squid/security/advisories/GHSA-pxwq-f3qr-w2xf

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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. However, a fully functional exploit for this vulnerability is available.