Mozilla Network Security Services SSLv2 ClientHello Processing Information Disclosure Vulnerability [CVE-2018-12384]

CVE Number – CVE-2018-12384

A vulnerability in the Mozilla Network Security Services (NSS) library could allow an unauthenticated, remote attacker to access sensitive information on a targeted system.

The vulnerability exists because the affected software could respond to an SSLv2-compatible ClientHello message with a ServerHello message that uses all zeros in place of random data. An attacker could exploit this vulnerability to conduct a passive replay attack by sending an SSLv2-compatible ClientHello message to a targeted system that is running an application compiled with the NSS library. A successful exploit could allow the attacker to access sensitive information.

Mozilla confirmed the vulnerability and released software updates.

  • To exploit this vulnerability, the attacker likely must be on the same, internal network in which the targeted system may reside. This access requirement may 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.

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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.

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