CVE-2018-5743
The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (6.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 6.46% probability · 94th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- f5/big-ip local traffic manager · f5/big-ip application acceleration manager · f5/big-ip advanced firewall manager · f5/big-ip analytics · f5/big-ip access policy manager · f5/big-ip application security manager · f5/big-ip edge gateway · f5/big-ip fraud protection service · f5/big-ip global traffic manager · f5/big-ip link controller · f5/big-ip webaccelerator · f5/big-ip policy enforcement manager · isc/bind · f5/enterprise manager · f5/big-iq centralized management · f5/iworkflow · f5/big-ip domain name system
- Source
- security-officer@isc.org
EPSS 6.5% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://kb.isc.org/docs/cve-2018-5743Third Party Advisory
- https://support.f5.com/csp/article/K74009656?utm_source=f5support&%3Butm_medium=RSS
- https://www.synology.com/security/advisory/Synology_SA_19_20
- https://kb.isc.org/docs/cve-2018-5743Third Party Advisory
- https://support.f5.com/csp/article/K74009656?utm_source=f5support&%3Butm_medium=RSS
- https://www.synology.com/security/advisory/Synology_SA_19_20
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.