A vulnerability in the deny-answer-aliases implementation of ISC BIND could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability is due to an assertion failure that could occur in the name.c code of the affected software related to the implementation of the deny-answer-aliases feature. An attacker could exploit this vulnerability by sending a request that submits malicious input to a targeted system. A successful exploit could trigger an assertion failure that causes performance degradation or other undesirable behavior, such as a recursion loop or excessive logging, leading to a DoS condition.
ISC.org has confirmed the vulnerability and released software updates.
To exploit this vulnerability, an attacker must send a malicious request to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.
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.
ISC.org has released a security advisory at the following link: AA-01639
ISC.org has released software updates at the following link: ISC BIND
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