SB2021060328 - Ubuntu update for squid
Published: June 3, 2021 Updated: May 1, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 vulnerabilities.
1) 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.
2) 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.
3) 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.
4) 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.
5) 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.
6) 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.
7) Input validation error (CVE-ID: CVE-2021-33620)
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:U/U:Green
The vulnerability allows a remote server to perform a denial of service (DoS) attack.
The vulnerability can be triggered by a header that can be expected to exist in HTTP traffic without any malicious intent by the server. A remote server can trigger the vulnerability and perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.