Denial of service in Squid



Published: 2020-08-23 | Updated: 2020-08-25
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2020-24606
CWE ID CWE-400
Exploitation vector Network
Public exploit N/A
Vulnerable software
Subscribe
Squid
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor Squid-cache.org

Security Advisory

Updated: 25.08.2020

Assigned CVE-ID and updated vulnerability description.

1) Resource exhaustion

Risk: Low

CVSSv3: 5.1 [CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2020-24606

CWE-ID: CWE-400 - Uncontrolled Resource Consumption ('Resource Exhaustion')

Exploit availability: No

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, 3.0.stable1, 3.0.stable2, 3.0.stable3, 3.0.stable4, 3.0.stable5, 3.0.stable6, 3.0.stable7, 3.0.stable8, 3.0.stable9, 3.0.stable10, 3.0.stable11, 3.0.stable12, 3.0.stable13, 3.0.stable14, 3.0.stable15, 3.0.stable16, 3.0.stable17, 3.0.stable18, 3.0.stable19, 3.0.stable20, 3.0.stable21, 3.0.stable22, 3.0.stable23, 3.0.stable24, 3.0.stable25, 3.0.stable26, 3.1, 3.1.0.1, 3.1.0.2, 3.1.0.3, 3.1.0.4, 3.1.0.5, 3.1.0.6, 3.1.0.7, 3.1.0.8, 3.1.0.9, 3.1.0.10, 3.1.0.11, 3.1.0.12, 3.1.0.13, 3.1.0.14, 3.1.0.15, 3.1.0.16, 3.1.0.17, 3.1.0.18, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.1.5, 3.1.5.1, 3.1.6, 3.1.7, 3.1.8, 3.1.9, 3.1.10, 3.1.11, 3.1.12, 3.1.12.1, 3.1.12.2, 3.1.12.3, 3.1.13, 3.1.14, 3.1.15, 3.1.16, 3.1.17, 3.1.18, 3.1.19, 3.1.20, 3.1.21, 3.1.22, 3.1.23, 3.2, 3.2.0.1, 3.2.0.2, 3.2.0.3, 3.2.0.4, 3.2.0.5, 3.2.0.6, 3.2.0.7, 3.2.0.8, 3.2.0.9, 3.2.0.10, 3.2.0.11, 3.2.0.12, 3.2.0.13, 3.2.0.14, 3.2.0.15, 3.2.0.16, 3.2.0.17, 3.2.0.18, 3.2.0.19, 3.2.1, 3.2.2, 3.2.3, 3.2.4, 3.2.5, 3.2.6, 3.2.7, 3.2.8, 3.2.9, 3.2.10, 3.2.11, 3.2.12, 3.2.13, 3.2.14, 3.3, 3.3.0, 3.3.0.1, 3.3.0.2, 3.3.0.3, 3.3.1, 3.3.2, 3.3.3, 3.3.4, 3.3.5, 3.3.6, 3.3.7, 3.3.8, 3.3.9, 3.3.10, 3.3.11, 3.3.12, 3.3.13, 3.3.14, 3.4, 3.4.0.1, 3.4.0.2, 3.4.0.3, 3.4.1, 3.4.2, 3.4.3, 3.4.4, 3.4.4.1, 3.4.4.2, 3.4.5, 3.4.6, 3.4.7, 3.4.8, 3.4.9, 3.4.10, 3.4.11, 3.4.12, 3.4.13, 3.4.14, 3.5, 3.5.0.1, 3.5.0.2, 3.5.0.3, 3.5.0.4, 3.5.1, 3.5.2, 3.5.3, 3.5.4, 3.5.5, 3.5.6, 3.5.7, 3.5.8, 3.5.9, 3.5.10, 3.5.11, 3.5.12, 3.5.13, 3.5.14, 3.5.15, 3.5.16, 3.5.17, 3.5.18, 3.5.19, 3.5.20, 3.5.21, 3.5.22, 3.5.23, 3.5.24, 3.5.25, 3.5.26, 3.5.27, 3.5.28, 4.0, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.0.5, 4.0.6, 4.0.7, 4.0.8, 4.0.9, 4.0.10, 4.0.11, 4.0.12, 4.0.13, 4.0.14, 4.0.15, 4.0.16, 4.0.17, 4.0.18, 4.0.19, 4.0.20, 4.0.21, 4.0.22, 4.0.23, 4.0.24, 4.0.25, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 4.10, 4.11, 4.12, 5.0, 5.0.1, 5.0.2, 5.0.3

CPE External links

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

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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