SB2021052636 - Gentoo update for Squid



SB2021052636 - Gentoo update for Squid

Published: May 26, 2021 Updated: May 1, 2026

Security Bulletin ID SB2021052636
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 7
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 7 vulnerabilities.


1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2020-25097)

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

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP requests. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.


2) Input validation error (CVE-ID: CVE-2021-28651)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


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. 


3) Memory leak (CVE-ID: CVE-2021-28652)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote client to perform DoS attack on the target system.

The vulnerability exists due memory leak due to incorrect parser validation in Cache Manager API. A remote trusted client with Cache Manager API access privilege can perform denial of service attack.


4) Input validation error (CVE-ID: CVE-2021-28662)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


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

The vulnerability exists due to insufficient input validation when processing HTTP responses. A remote attacker who controls a malicious web page can send specially crafted HTTP response and perform a denial of service attack against the proxy server. The issue trigger is a header which can be expected to exist in HTTP traffic without any malicious intent by the server.


5) Input validation error (CVE-ID: CVE-2021-31806)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Green


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

The vulnerability exists due to insufficient validation of user-supplied input when performing HTTP Range requests. A remote proxy client can send specially crafted HTTP request via the proxy server  and perform a denial of service (DoS) attack.


6) Resource management error (CVE-ID: CVE-2021-31807)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Green


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

The vulnerability exists due to improper management of memory within the application when processing HTTP Range header. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.


7) Integer overflow (CVE-ID: CVE-2021-31808)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


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

The vulnerability exists due to insufficient validation of user-supplied input when delivering responses from HTTP Range requests. A remote proxy client can send specially crafted HTTP request via the proxy server, force the server to initiate a necessary response, trigger integer overflow in Squid and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.