Resource management error in Squid-cache Squid

Published: 2011-11-17 | Updated: 2020-08-11
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2011-4096
Exploitation vector Network
Public exploit N/A
Vulnerable software
Server applications / IDS/IPS systems, Firewalls and proxy servers


Security Advisory

This security advisory describes one medium risk vulnerability.

1) Resource management error

Risk: Medium

CVSSv3: 4.6 [CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2011-4096

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No


The vulnerability allows a remote non-authenticated attacker to perform service disruption.

The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service (daemon abort) via a DNS reply containing a CNAME record that references another CNAME record that contains an empty A record.


Install update 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, 3.1,,,,,,,,,,,,,,,,,,, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.1.5,, 3.1.6, 3.1.7, 3.1.8, 3.1.9, 3.1.10, 3.1.11, 3.1.12, 3.1.13, 3.1.14

CPE External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker 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.