Allocation of Resources Without Limits or Throttling in ISC BIND - CVE-2018-5743

Detailed vulnerability description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers. Unfortunately, the code which was intended to limit the number of simultaneous connections contained an error which could be exploited to grow the number of simultaneous connections beyond this limit. Versions affected: BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.6, 9.12.0 -> 9.12.4, 9.14.0. BIND 9 Supported Preview Edition versions 9.9.3-S1 -> 9.11.5-S3, and 9.11.5-S5. Versions 9.13.0 -> 9.13.7 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5743.

How to mitigate CVE-2018-5743

Sources

• https://kb.isc.org/docs/cve-2018-5743
• https://support.f5.com/csp/article/K74009656?utm_source=f5support&utm_medium=RSS
• https://www.synology.com/security/advisory/Synology_SA_19_20