Debian update for squid

1) Buffer overflow

EUVDB-ID: #VU20445

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12525

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input passed via the Proxy-Authorization header when Squid is configured to use HTTP Digest authentication . A remote attacker can send specially crafted HTTP request to the proxy server and perform denial of service attack.

Mitigation

Update the affected package to version: 4.6-1+deb10u1.

Vulnerable software versions

squid (Debian package): 4.0.21-1~exp5 - 4.6-1

External links

http://www.debian.org/security/2019/dsa-4507

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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

2) Heap-based buffer overflow

EUVDB-ID: #VU19169

Risk: High

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

CVE-ID: CVE-2019-12527

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 checking Basic Authentication with HttpHeader::getAuth. A remote attacker can send an overly long authentication string, 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

Update the affected package to version: 4.6-1+deb10u1.

Vulnerable software versions

squid (Debian package): 4.0.21-1~exp5 - 4.6-1

External links

http://www.debian.org/security/2019/dsa-4507

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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

3) Out-of-bounds read

EUVDB-ID: #VU20460

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-2019-12529

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition when parsing username in the Proxy-Authorization header during HTTP Basic authentication. A remote attacker can send specially crafted request to the Squid proxy server and retrieve parts of memory contents, if the Squid maintainer had configured the display of usernames on error pages.

Mitigation

Update the affected package to version: 4.6-1+deb10u1.

Vulnerable software versions

squid (Debian package): 4.0.21-1~exp5 - 4.6-1

External links

http://www.debian.org/security/2019/dsa-4507

Q & A

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.

4) Out-of-bounds read

EUVDB-ID: #VU20461

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-12854

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition when terminating strings in cachemgr.cgi. A remote attacker can a specially crafted request to the affected proxy server, trigger out-of-bounds read error and crash the CGI process, denying access to all users on systems with memory access protections.

Mitigation

Update the affected package to version: 4.6-1+deb10u1.

Vulnerable software versions

squid (Debian package): 4.0.21-1~exp5 - 4.6-1

External links

http://www.debian.org/security/2019/dsa-4507

Q & A

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.

5) Cross-site scripting

EUVDB-ID: #VU19140

Risk: Medium

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-13345

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data passed via the  the "user_name" and "auth" parameters to the cachemgr.cgi web module. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Example:

http://[host]/cgi-bin/cachemgr.cgi?host=localhost&port=3128&user_name=admin&operation=authenticate&auth=bG9jYWxob3N0fDE1NTg5NTYzNzJ8YWRtIj48c2NyaXB0PmFsZXJ0KCdYU1MnKTwvc2NyaXB0PmlufGRzZGFkYWE=

Mitigation

Update the affected package to version: 4.6-1+deb10u1.

Vulnerable software versions

squid (Debian package): 4.0.21-1~exp5 - 4.6-1

External links

http://www.debian.org/security/2019/dsa-4507

Q & A

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. However, proof of concept for this vulnerability is available.