Vulnerability identifier: #VU32025
Vulnerability risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-770
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
ISC BIND
Server applications /
DNS servers
Vendor: ISC
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.
Mitigation
Install update from vendor's website.
Vulnerable software versions
ISC BIND: 9.9.8-P3
External links
http://kb.isc.org/docs/cve-2018-5743
http://support.f5.com/csp/article/K74009656?utm_source=f5support&utm_medium=RSS
http://www.synology.com/security/advisory/Synology_SA_19_20
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.