#VU20445 Buffer overflow in Squid - CVE-2019-12525

Vulnerability identifier: #VU20445

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-12525

CWE-ID: CWE-119

Exploitation vector: Local 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 insufficient validation of user-supplied input passed via the Proxy-Authorization header when Squid is configured to use HTTP Digest authentication . A remote attacker can send specially crafted HTTP request to the proxy server and perform denial of service attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 3.3.4 - 3.5.28, 4.0.1 - 4.7

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External links
https://www.squid-cache.org/Versions/v4/changesets/
https://www.squid-cache.org/Versions/v4/changesets/squid-4-7f73e9c5d17664b882ed32590e6af310c247f320.patch
https://github.com/squid-cache/squid/commits/v4
https://lists.debian.org/debian-lts-announce/2019/07/msg00018.html
https://usn.ubuntu.com/4065-1/
https://usn.ubuntu.com/4065-2/

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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 local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.