--- title: "CVE-2022-3736: named configured to answer from stale cache may termina" slug: "cve-2022-3736" description: "BIND 9 resolver can crash when stale cache and stale answers are enabled, option stale-answer-client-timeout is set to a positive integer, and the resolver receives an RRSIG query." updated: 2023-01-25T14:19:21Z published: 2023-01-25T14:19:21Z canonical: "kb.isc.org/cve-2022-3736" --- > ## Documentation Index > Fetch the complete documentation index at: https://kb.isc.org/llms.txt > Use this file to discover all available pages before exploring further. # CVE-2022-3736: named configured to answer from stale cache may terminate unexpectedly while processing RRSIG queries **CVE:** [CVE-2022-3736](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3736) **Document version:** 2.0 **Posting date:** 25 January 2023 **Program impacted:** [BIND 9](https://www.isc.org/bind/) **Versions affected:** BIND - 9.16.12 -> 9.16.36 - 9.18.0 -> 9.18.10 - 9.19.0 -> 9.19.8 BIND Supported Preview Edition - 9.16.12-S1 -> 9.16.36-S1 (The flaw exists in the implementation of the `stale-answer-client-timeout` option, which was first effectively introduced in BIND 9.16.12 and BIND 9.16.12-S1. That option is also configurable in BIND 9.11.33-S1 and newer BIND 9.11-S versions, but it is always replaced with 0 in all BIND 9.11.x-S1 releases.) **Severity:** High **Exploitable:** Remotely **Description:** BIND 9 resolver can crash when stale cache and stale answers are enabled, option `stale-answer-client-timeout` is set to a positive integer, and the resolver receives an RRSIG query. **Impact:** By sending specific queries to the resolver, an attacker can cause `named` to crash. **CVSS Score:** 7.5 **CVSS Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: [https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H&version=3.1](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H&version=3.1). **Workarounds:** Setting `stale-answer-client-timeout` to `0` or to `off/disabled` will prevent BIND from crashing due to this issue. **Active exploits:** We are not aware of any active exploits. **Solution:** Upgrade to the patched release most closely related to your current version of BIND 9: - 9.16.37 - 9.18.11 - 9.19.9 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. - 9.16.37-S1 **Acknowledgments:** ISC would like to thank Borja Marcos from Sarenet (with assistance by Iratxe Niño from Fundación Sarenet) for bringing this vulnerability to our attention. **Document revision history:** - 1.0 Early Notification, 18 January 2023 - 2.0 Public disclosure, 25 January 2023 **Related documents:** See our [BIND 9 Security Vulnerability Matrix](https://kb.isc.org/docs/aa-00913) for a complete listing of security vulnerabilities and versions affected. **Do you still have questions?** Questions regarding this advisory should be mailed to [security-officer@isc.org](mailto:security-officer@isc.org). *To report a new issue, please encrypt your message using security-officer@isc.org's PGP key, which can be found here: [https://www.isc.org/pgpkey/](https://www.isc.org/pgpkey/). If you are unable to use encrypted email you may also report new issues at: [https://www.isc.org/reportbug/](https://www.isc.org/reportbug/).* **Note:** ISC patches only currently supported versions. When possible we indicate EOL versions affected. For current information on which versions are actively supported, please see [https://www.isc.org/download/](https://www.isc.org/download/). **ISC Security Vulnerability Disclosure Policy:** Details of our current security advisory policy and practice can be found in the ISC Software Defect and Security Vulnerability Disclosure Policy at [https://kb.isc.org/docs/aa-00861](https://kb.isc.org/docs/aa-00861). The Knowledgebase article [https://kb.isc.org/docs/cve-2022-3736](https://kb.isc.org/docs/cve-2022-3736) is the complete and official security advisory document. **Legal Disclaimer:** Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. 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