#VU45957 Resource exhaustion in Squid - CVE-2020-24606

Vulnerability identifier: #VU45957

Vulnerability risk: Low

CVSSv4.0: 1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/E:U/U:Clear]

CVE-ID: CVE-2020-24606

CWE-ID: CWE-400

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 application does not properly EOF in peerDigestHandleReply() function in peer_digest.cc when processing Cache Digest response messages from a trusted peer. A remote attacker who controls a trusted peer can consume all available CPU cycles and perform a denial of service (DoS) attack.

This attack is limited to Squid using cache_peer with cache digests feature.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0.stable1 - 3.5.28, 4.0 - 4.12, 5.0 - 5.0.3

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External links
https://github.com/squid-cache/squid/security/advisories/GHSA-vvj7-xjgq-g2jg/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

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