Vulnerability identifier: #VU53017
Vulnerability risk: Medium
CVSSv3.1: 6.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-20
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 insufficient input validation when resolving "urn:" resource identifiers. A remote attacker can trick a user behind the proxy server to click on a specially crafted "urn:" link that leads to a server under attacker's control and force Squid to consume arbitrarily large amounts of memory on the server.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
Squid: 5.0 - 5.0.5, 4.0 - 4.14, 3.0 - 3.5.28, 2.7 - 2.7.STABLE9, 2.6 - 2.6.stable24, 2.5 - 2.5_stable9, 2.4 - 2.4_stable_3, 2.3 - 2.3_stable5, 2.2 - 2.2.stable5, 2.1 - 2.1_patch2, 2.0 - 2.0_patch2
External links
http://github.com/squid-cache/squid/security/advisories/GHSA-ch36-9jhx-phm4/
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.