Red Hat Security Advisory 2024-9644-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8. Issues addressed include a denial of service vulnerability.

Ubuntu Security Notice 6857-1 - 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. This issue only affected Ubuntu 16.04 LTS. It was discovered that Squid incorrectly handled SSPI and SMB authentication. A remote attacker could use this issue to cause Squid to crash, resulting in a denial of service, or possibly obtain sensitive information. This issue only affected Ubuntu 16.04 LTS.

Red Hat Security Advisory 2024-2822-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.8 Extended Update Support. Issues addressed include a denial of service vulnerability.

Ubuntu Security Notice 6728-3 - USN-6728-1 fixed vulnerabilities in Squid. The fix for CVE-2023-5824 caused Squid to crash in certain environments on Ubuntu 20.04 LTS and was disabled in USN-6728-2. The problematic fix for CVE-2023-5824 has now been corrected and reinstated in this update.

Red Hat Security Advisory 2024-1833-03 - An update for squid is now available for Red Hat Enterprise Linux 9.0 Extended Update Support. Issues addressed include a denial of service vulnerability.

Red Hat Security Advisory 2024-1832-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Telecommunications Update Service, and Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions. Issues addressed include a denial of service vulnerability.

Red Hat Security Advisory 2024-1787-03 - An update for squid is now available for Red Hat Enterprise Linux 7. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-1515-03 - An update for squid is now available for Red Hat Enterprise Linux 9.2 Extended Update Support. Issues addressed include a denial of service vulnerability.

Debian Linux Security Advisory 5637-1 - Several security vulnerabilities have been discovered in Squid, a full featured web proxy cache. Due to programming errors in Squid's HTTP request parsing, remote attackers may be able to execute a denial of service attack by sending large X-Forwarded-For header or trigger a stack buffer overflow while performing HTTP Digest authentication. Other issues facilitate request smuggling past a firewall or a denial of service against Squid's Helper process management.

Debian Linux Security Advisory 5637-1 - Several security vulnerabilities have been discovered in Squid, a full featured web proxy cache. Due to programming errors in Squid's HTTP request parsing, remote attackers may be able to execute a denial of service attack by sending large X-Forwarded-For header or trigger a stack buffer overflow while performing HTTP Digest authentication. Other issues facilitate request smuggling past a firewall or a denial of service against Squid's Helper process management.

Debian Linux Security Advisory 5637-1 - Several security vulnerabilities have been discovered in Squid, a full featured web proxy cache. Due to programming errors in Squid's HTTP request parsing, remote attackers may be able to execute a denial of service attack by sending large X-Forwarded-For header or trigger a stack buffer overflow while performing HTTP Digest authentication. Other issues facilitate request smuggling past a firewall or a denial of service against Squid's Helper process management.

Red Hat Security Advisory 2024-1184-03 - An update for squid is now available for Red Hat Enterprise Linux 9.2 Extended Update Support. Issues addressed include a denial of service vulnerability.

Red Hat Security Advisory 2024-1153-03 - An update for squid is now available for Red Hat Enterprise Linux 9.0 Extended Update Support. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-1062-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.8 Extended Update Support. Issues addressed include a denial of service vulnerability.

Red Hat Security Advisory 2024-0773-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Telecommunications Update Service, and Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-0772-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.2 Advanced Update Support, Red Hat Enterprise Linux 8.2 Telecommunications Update Service, and Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-0771-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.6 Extended Update Support. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-0397-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8.8 Extended Update Support. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2024-0072-03 - An update for squid is now available for Red Hat Enterprise Linux 9.2 Extended Update Support. Issues addressed include buffer over-read, denial of service, and null pointer vulnerabilities.

Red Hat Security Advisory 2023-7668-03 - An update for the squid:4 module is now available for Red Hat Enterprise Linux 8. Issues addressed include a denial of service vulnerability.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Affected versions of squid are subject to a a Use-After-Free bug which can lead to a Denial of Service attack via collapsed forwarding. All versions of Squid from 3.5 up to and including 5.9 configured with "collapsed_forwarding on" are vulnerable. Configurations with "collapsed_forwarding off" or without a "collapsed_forwarding" directive are not vulnerable. This bug is fixed by Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should remove all collapsed_forwarding lines from their squid.conf.

Squid is vulnerable to Denial of Service attack against HTTP and HTTPS clients due to an Improper Handling of Structural Elements bug.