Ncurses next_char Function Infinite Loop Remote Denial of Service Vulnerability [CVE-2017-13728]

CVE Number = CVE-2017-13728

A vulnerability in the next_char() function of ncurses could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability is due to insufficient validation of user-supplied input that is processed by the next_char() function, as defined in the comp_scan.c source code file of the affected software. An attacker could exploit this vulnerability by sending a request that submits malicious input to the affected software on a targeted system. A successful exploit could cause an infinite loop condition, which could be used to cause the affected software to stop responding, resulting in a DoS condition.

Proof-of-concept code that demonstrates an exploit of this vulnerability is publicly available.

Ncurses has confirmed the vulnerability and released software updates.

• To exploit this vulnerability, the attacker must send a request that submits malicious input to the targeted system, which may require access to trusted, internal networks. This access requirement could reduce the likelihood of a successful exploit.

• 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.

• Ncurses has released a changelog at the following link: 20170826

• Ncurses has released software updates at the following link: ncurses 6.1
  
  
  
  
  

Duncan

Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.