SB2019112524 - Fedora 31 update for squid
Published: November 25, 2019 Updated: April 25, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 secuirty vulnerabilities.
1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2019-18678)
The vulnerability allows a remote attacker to perform HTTP request smuggling attack.
The vulnerability exists due to insufficient validation of HTTP request headers in Squid. A remote attacker can initiate a specially crafted HTTP request that will cause the software to split HTTP request and display to the end user content, controlled by the attacker at arbitrary URL.
2) Heap-based buffer overflow (CVE-ID: CVE-2019-12526)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing URN requests. A remote attacker can send specially crafted request to the Squid client, 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.
3) Information disclosure (CVE-ID: CVE-2019-18679)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to incorrect data management when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer which sits within heap memory allocation. This allows a remote attacker to gain knowledge of memory allocations and bypass ASLR protection and help in exploitation of other vulnerabilities.
4) Cross-site request forgery (CVE-ID: CVE-2019-18677)
The vulnerability allows a remote attacker to perform cross-site request forgery attacks.
The vulnerability exists due to insufficient validation of the HTTP request origin, when Squid is configured with the append_domain option. A remote attacker can trick the victim to visit a specially crafted web page and redirect victim's traffic to a third-party domain.
5) Input validation error (CVE-ID: CVE-2019-12523)
The vulnerability allows a remote attacker to bypass certain security restrictions.
The vulnerability exists due to insufficient validation of user-supplied input when processing URIs. A remote authenticated attacker can add certain characters to the URI, bypass implemented security restrictions and access restricted websites.
6) Input validation error (CVE-ID: CVE-2019-18676)
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to insufficient validation of user-supplied input when processing URIs. A remote attacker can create a specially crafted link, trick the victim into visiting it, trigger buffer overflow and crash the Squid process.
Remediation
Install update from vendor's website.