# What is CVE-2018-5743? > CVE-2018-5743 is a high-severity flaw (CVSS 7.5) in Bind from Isc, published on 9 October 2019. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 6.5%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2018-5743 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **Precursor Intelligence risk score:** 49 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 7.5 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 6.5% (latest exploit-likelihood forecast) - **Published:** 9 October 2019 - **Record last updated:** 7 November 2023 - **Main product:** Bind from Isc - **Affected products:** 17 ## What is CVE-2018-5743? In plain terms It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline. ### The official 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. ### What kind of flaw is it? - CWE-770: Allocation of Resources Without Limits or Throttling ### How an attack on it works - Where an attacker can be: Anywhere on the internet - How hard it is to pull off: Easy: no special conditions - Login needed first: No login needed - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can take it offline Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` ## Is CVE-2018-5743 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 6.5%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 6.5%, 6.5%, 6.5%, 6.5%, 6.5%, 6.5%, 6.5%. ### Timeline - 9 October 2019: Published - 7 November 2023: Record last updated ### How Precursor Intelligence ranks it CVE-2018-5743 scores **49 out of 100 (Medium)**, with the action "Plan remediation". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: smaller factor - Threat activity around it: smaller factor 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2018-5743? The published record lists 17 products. - [Bind](https://www.precursorintelligence.com/product/isc/bind) by [Isc](https://www.precursorintelligence.com/vendors/isc) (Application): 9.9.0 to 9.10.8, 9.10.8-p1, 9.11.0 to 9.11.6, 9.12.0 to 9.12.4, 9.13.0 to 9.13.7, 9.14.0 - [Big-IP Access Policy Manager](https://www.precursorintelligence.com/product/f5/big-ip_access_policy_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.1.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Advanced Firewall Manager](https://www.precursorintelligence.com/product/f5/big-ip_advanced_firewall_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.1.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Analytics](https://www.precursorintelligence.com/product/f5/big-ip_analytics) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Application Acceleration Manager](https://www.precursorintelligence.com/product/f5/big-ip_application_acceleration_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Application Security Manager](https://www.precursorintelligence.com/product/f5/big-ip_application_security_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.1, 15.0.0 - [Big-IP Domain Name System](https://www.precursorintelligence.com/product/f5/big-ip_domain_name_system) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.1.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Edge Gateway](https://www.precursorintelligence.com/product/f5/big-ip_edge_gateway) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Fraud Protection Service](https://www.precursorintelligence.com/product/f5/big-ip_fraud_protection_service) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Global Traffic Manager](https://www.precursorintelligence.com/product/f5/big-ip_global_traffic_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Link Controller](https://www.precursorintelligence.com/product/f5/big-ip_link_controller) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Local Traffic Manager](https://www.precursorintelligence.com/product/f5/big-ip_local_traffic_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.0.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Policy Enforcement Manager](https://www.precursorintelligence.com/product/f5/big-ip_policy_enforcement_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.1.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-IP Webaccelerator](https://www.precursorintelligence.com/product/f5/big-ip_webaccelerator) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 11.5.2 to 11.6.5, 12.1.0 to 12.1.4, 13.1.0 to 13.1.1, 14.0.0 to 14.1.0, 15.0.0 - [Big-Iq Centralized Management](https://www.precursorintelligence.com/product/f5/big-iq_centralized_management) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 5.0.0 to 5.4.0, 6.0.0 to 6.1.0 - [Enterprise Manager](https://www.precursorintelligence.com/product/f5/enterprise_manager) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 3.1.1 - [Iworkflow](https://www.precursorintelligence.com/product/f5/iworkflow) by [F5](https://www.precursorintelligence.com/vendors/f5) (Application): 2.3.0 ## How do I fix CVE-2018-5743? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the latest update from the vendor. The references list where the vendor has published details. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [kb.isc.org](https://kb.isc.org/docs/cve-2018-5743) (Third-party advisory) - [support.f5.com](https://support.f5.com/csp/article/K74009656?utm_source=f5support&%3Butm_medium=RSS) - [synology.com](https://www.synology.com/security/advisory/Synology_SA_19_20) ## Questions ### What is CVE-2018-5743? CVE-2018-5743 is a high-severity flaw in Bind from Isc, published on 9 October 2019. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline. ### How serious is CVE-2018-5743? It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2018-5743 is 49 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2018-5743 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 6.5%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2018-5743 affect? For Bind from Isc: 9.9.0 to 9.10.8, 9.10.8-p1, 9.11.0 to 9.11.6, 9.12.0 to 9.12.4, 9.13.0 to 9.13.7, 9.14.0. The record lists 17 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2018-5743? Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. ## Does CVE-2018-5743 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact