SB2019082403 - Debian update for squid
Published: August 24, 2019 Updated: September 2, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Buffer overflow (CVE-ID: CVE-2019-12525)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input passed via the Proxy-Authorization header when Squid is configured to use HTTP Digest authentication . A remote attacker can send specially crafted HTTP request to the proxy server and perform denial of service attack.
2) Heap-based buffer overflow (CVE-ID: CVE-2019-12527)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when checking Basic Authentication with HttpHeader::getAuth. A remote attacker can send an overly long authentication string, 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) Out-of-bounds read (CVE-ID: CVE-2019-12529)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when parsing username in the Proxy-Authorization header during HTTP Basic authentication. A remote attacker can send specially crafted request to the Squid proxy server and retrieve parts of memory contents, if the Squid maintainer had configured the display of usernames on error pages.
4) Out-of-bounds read (CVE-ID: CVE-2019-12854)
The vulnerability allows a remote attacker to perform denial of service (DoS) attack.
The vulnerability exists due to a boundary condition when terminating strings in cachemgr.cgi. A remote attacker can a specially crafted request to the affected proxy server, trigger out-of-bounds read error and crash the CGI process, denying access to all users on systems with memory access protections.
5) Cross-site scripting (CVE-ID: CVE-2019-13345)
The vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data passed via the the "user_name" and "auth" parameters to the cachemgr.cgi web module. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Example:
http://[host]/cgi-bin/cachemgr.cgi?host=localhost&port=3128&user_name=admin&operation=authenticate&auth=bG9jYWxob3N0fDE1NTg5NTYzNzJ8YWRtIj48c2NyaXB0PmFsZXJ0KCdYU1MnKTwvc2NyaXB0PmlufGRzZGFkYWE=
Remediation
Install update from vendor's website.