Wireshark ASN.1 BER Dissector Denial of Service Vulnerability [CVE-2019-13619]

CVE number – CVE-2019-13619

A vulnerability in the Abstract Syntax Notation One (ASN.1) Basic Encoding Rules (BER) dissector component of Wireshark could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability exists because the epan/asn1.c source code file of the affected software does not properly restrict buffer increments. An attacker could exploit this vulnerability by injecting a malformed packet into a network to be processed by the affected software, or by convincing a user to open a malicious packet trace file. A successful exploit could result in a DoS condition on the targeted system. 

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

Wireshark has confirmed the vulnerability and released software updates.

Analysis

• To exploit the vulnerability, the attacker may use misleading language or instructions to convince a user to open a malicious packet trace file. To inject malformed packets that Wireshark may attempt to parse, the attacker may need access to the same trusted, internal network where the targeted system resides. This access requirement may reduce the likelihood of a successful exploit.

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

• Wireshark has released a security advisory at the following link: wnpa-sec-2019-20

Fixed Software

• Wireshark has released software updates at the following link: Wireshark 3.0.3, 2.6.10, and 2.4.16