Squid Basic Authentication Information Disclosure Vulnerability [CVE-2019-12529]

CVE Number – CVE-2019-12529

A vulnerability in Squid could allow an unauthenticated, remote attacker to access sensitive information on a targeted system. The vulnerability exists because the affected software does not properly check proxy-authentication header length when basic authentication is enabled. An attacker could exploit this vulnerability by submitting a crafted HTTP request to the targeted system. A successful exploit could allow the attacker to access sensitive information.Squid has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, an attacker must send an HTTP request that submits malicious input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
  
  Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
  
  Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
  
  Administrators are advised to monitor affected systems.

Vendor Announcements

• Squid has released a commit at the following link: Commit dd46b5417809647f561d8a5e0e74c3aacd235258

Fixed Software

• Squid has released a software patch at the following link: Replace uudecode with libnettle base64 decoder (#406)