An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.

Affected: Ubuntu:18.04:LTS: squid3, Ubuntu:20.04:LTS: squid

Joshua Rogers discovered that Squid incorrectly handled requests with the urn: scheme. A remote attacker could possibly use this issue to cause Squid to consume resources, leading to a denial of service. (CVE-2021-28651)

Joshua Rogers discovered that Squid incorrectly handled requests to the Cache Manager API. A remote attacker with access privileges could possibly use this issue to cause Squid to consume resources, leading to a denial of service. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28652)

Joshua Rogers discovered that Squid incorrectly handled certain response headers. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue was only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662)

Joshua Rogers discovered that Squid incorrectly handled range request processing. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-31806, CVE-2021-31807, CVE-2021-31808)

Joshua Rogers discovered that Squid incorrectly handled certain HTTP responses. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-33620)