Multiple vulnerabilities in Squid proxy server

1) Information disclosure

EUVDB-ID: #VU22589

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18679

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to incorrect data management when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer which sits within heap memory allocation. This allows a remote attacker to gain knowledge of memory allocations and bypass ASLR protection and help in exploitation of other vulnerabilities.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0 - 4.8

External links

http://www.squid-cache.org/Advisories/SQUID-2019_11.txt

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.

2) Inconsistent interpretation of HTTP requests

EUVDB-ID: #VU22587

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18678

CWE-ID: CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform HTTP request smuggling attack.

The vulnerability exists due to insufficient validation of HTTP request headers in Squid. A remote attacker can initiate a specially crafted HTTP request that will cause the software to split HTTP request and display to the end user content, controlled by the attacker at arbitrary URL.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0 - 4.8

External links

http://www.squid-cache.org/Advisories/SQUID-2019_10.txt

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.

3) Heap-based buffer overflow

EUVDB-ID: #VU22585

Risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12526

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing URN requests. A remote attacker can send specially crafted request to the Squid client, trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0 - 4.8

External links

http://www.squid-cache.org/Advisories/SQUID-2019_7.txt

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.

4) Cross-site request forgery

EUVDB-ID: #VU22910

Risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18677

CWE-ID: CWE-352 - Cross-Site Request Forgery (CSRF)

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform cross-site request forgery attacks.

The vulnerability exists due to insufficient validation of the HTTP request origin, when Squid is configured with the append_domain option. A remote attacker can trick the victim to visit a specially crafted web page and redirect victim's traffic to a third-party domain.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 2.7 RC2 - 4.9

External links

http://www.squid-cache.org/Advisories/SQUID-2019_9.txt

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.

5) Input validation error

EUVDB-ID: #VU22909

Risk: Medium

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18676

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing URIs. A remote attacker can create a specially crafted link, trick the victim into visiting it, trigger buffer overflow and crash the Squid process.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0.stable1 - 4.8

External links

http://www.squid-cache.org/Advisories/SQUID-2019_8.txt

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.

6) Input validation error

EUVDB-ID: #VU22908

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12523

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to insufficient validation of user-supplied input when processing URIs. A remote authenticated attacker can add certain characters to the URI, bypass implemented security restrictions and access restricted websites.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Squid: 3.0.stable1 - 4.8

External links

http://www.squid-cache.org/Advisories/SQUID-2019_8.txt

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated 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.