===================================================================== CERT-Renater Note d'Information No. 2021/VULN119 _____________________________________________________________________ DATE : 17/03/2022 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running ISC BIND versions prior to 9.11.37, 9.16.27, 9.18.1, 9.11.37-S1, 9.16.27-S1. ===================================================================== https://kb.isc.org/docs/cve-2021-25220 https://kb.isc.org/v1/docs/cve-2022-0396 https://kb.isc.org/docs/cve-2022-0635 https://kb.isc.org/docs/cve-2022-0667 _____________________________________________________________________ CVE-2021-25220: DNS forwarders - cache poisoning vulnerability Updated on 16 Mar 2022 3 Minutes to read Contributors Greg ChoulesMark Andrews CVE: CVE-2021-25220 Document version: 2.0 Posting date: 16 March 2022 Program impacted: BIND Versions affected: BIND 9.11.0 -> 9.11.36 9.12.0 -> 9.16.26 9.17.0 -> 9.18.0 BIND Supported Preview Editions: 9.11.4-S1 -> 9.11.36-S1 9.16.8-S1 -> 9.16.26-S1 Versions of BIND 9 earlier than those shown - back to 9.1.0, including Supported Preview Editions - are also believed to be affected but have not been tested as they are EOL. Severity: Medium Exploitable: Remotely Description: When using forwarders, bogus NS records supplied by, or via, those forwarders may be cached and used by named if it needs to recurse for any reason, causing it to obtain and pass on potentially incorrect answers. Some examples of configurations that will be vulnerable are: Resolvers using per zone or global forwarding with forward first (forward first is the default). Resolvers not using global forwarding, but with per-zone forwarding with either forward first (the default) or forward only. Resolvers configured with global forwarding along with zone statements that disable forwarding for part of the DNS namespace. Authoritative-only BIND 9 servers are not vulnerable to this flaw. Impact: The cache could become poisoned with incorrect records leading to queries being made to the wrong servers, which might also result in false information being returned to clients. CVSS Score: 6.2 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N/E:U/RL:U/RC:C 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:H/UI:N/S:C/C:N/I:H/A:N/E:U/RL:U/RC:C&version=3.1. Workarounds: If applicable, modify your configuration to either remove all forwarding or all possibility of recursion. Depending on your use-case, it may be possible to use other zone types to replace forward zones. 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: BIND 9.11.37 BIND 9.16.27 BIND 9.18.1 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.37-S1 BIND 9.16.27-S1 Acknowledgments: ISC would like to thank Xiang Li, Baojun Liu, and Chaoyi Lu from Network and Information Security Lab, Tsinghua University and Changgen Zou from Qi An Xin Group Corp. for discovering and reporting this issue. Document revision history: 1.0 Early Notification, 9 March 2022 1.1 Correction to official document link, 16 March 2022 2.0 Public disclosure, 16 March 2022 Related documents: See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected. Do you still have questions? Questions regarding this advisory should go to 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/. If you are unable to use encrypted email, you may also report new issues at: 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/.) 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. The Knowledgebase article https://kb.isc.org/docs/cve-2021-25220 is the complete and official security advisory document. Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time. A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors. _____________________________________________________________________ CVE-2022-0396: DoS from specifically crafted TCP packets Updated on 16 Mar 2022 2 Minutes to read Contributors Greg ChoulesDan Theisen CVE: CVE-2022-0396 Document version: 2.0 Posting date: 16 March 2022 Program impacted: BIND Versions affected: BIND 9.16.11 -> 9.16.26, 9.17.0 -> 9.18.0 and versions 9.16.11-S1 -> 9.16.26-S1 of the BIND Supported Preview Edition. Severity: Medium Exploitable: Remotely Description: ISC recently discovered an issue in BIND that allows TCP connection slots to be consumed for an indefinite time frame via a specifically crafted TCP stream sent from a client. This issue is present in BIND 9.16.11 to 9.16.26 (including S editions), and 9.18.0. This issue can only be triggered on BIND servers which have keep-response-order enabled, which is not the default configuration. The keep-response-order option is an ACL block; any hosts which are specified within it will be able to trigger this issue on affected versions. Impact: Specifically crafted TCP streams can cause connections to BIND to remain in CLOSE_WAIT status for an indefinite period of time, even after the client has terminated the connection. CVSS Score: 4.9 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:F/RL:O/RC:C 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:L/E:F/RL:O/RC:C&version=3.1. Workarounds: To mitigate this issue in all affected versions of BIND, use the default setting of keep-response-order { none; }. 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: 9.16.27 9.18.1 BIND Supported Preview Edition is a special feature-preview branch of BIND provided to eligible ISC support customers. 9.16.27-S1 Document revision history: 1.0 Early Notification, 9 March 2022 1.1 Grammatical edit to Description, 16 March 2022 2.0 Public disclosure, 16 March 2022 Related documents: See CVE-2019-6477: TCP-pipelined queries can bypass tcp-clients limit for more information regarding CVE-2019-6477, in which ISC recommended setting keep-response-order to any to work around a previous issue where BIND was not respecting the TCP client limit. See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected. Do you still have questions? Questions regarding this advisory should go to 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/. If you are unable to use encrypted email, you may also report new issues at: 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/.) 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. The Knowledgebase article https://kb.isc.org/docs/cve-2022-0396 is the complete and official security advisory document. Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time. A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors. _____________________________________________________________________ CVE-2022-0635: DNAME insist with synth-from-dnssec enabled Updated on 16 Mar 2022 2 Minutes to read Contributors Greg ChoulesCathy Almond CVE: CVE-2022-0635 Document version: 2.0 Posting date: 16 March 2022 Program impacted: BIND Versions affected: BIND 9.18.0 Severity: High Exploitable: Remotely Description: We refactored the RFC 8198 Aggressive Use of DNSSEC-Validated Cache feature (synth-from-dnssec) for the new BIND 9.18.0 stable release, and changed the default so that is now automatically enabled for dnssec-validating resolvers. Subsequently it was found that repeated patterns of specific queries to servers with this feature enabled could cause an INSIST failure in query.c:query_dname which causes named to terminate unexpectedly. The vulnerability affects BIND resolvers running 9.18.0 that have both dnssec-validation and synth-from-dnssec enabled. (Note that dnssec-validation auto; is the default setting unless configured otherwise in named.conf and that enabling dnssec-validation automatically enables synth-from-dnssec unless explicitly disabled) Impact: When a vulnerable version of named receives a series of specific queries, the named process will eventually terminate due to a failed assertion check. CVSS Score: 7.0 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:F/RL:O/RC:C 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/E:F/RL:O/RC:C&version=3.1. Workarounds: The failure can be avoided by adding this option to named.conf: synth-from-dnssec no; Text However we do not recommend disabling this feature other than as a temporary workaround because it provides protection from pseudo-random-subdomain attacks against DNSSEC-signed zones. Active exploits: We are not aware of any active exploits. Solution: Users of BIND 9.18.0 should upgrade to BIND 9.18.1 Acknowledgments: ISC would like to thank Vincent Levigneron of AFNIC for reporting this issue to us and for verifying the fix and workaround. Document revision history: 1.0 Early Notification, 9 March 2022 2.0 Public disclosure, 16 March 2022 Related documents: See Operational Notification: synth-from-dnssec may cause slow resolution on resolvers under certain cache conditions for more information regarding early BIND support for RFC 8198 Aggressive Use of DNSSEC-Validated Cache and our recommendation that this feature be disabled until versions of BIND were made available which contain an improvement to the synth-from-dnssec feature. See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected. Do you still have questions? Questions regarding this advisory should go to 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/. If you are unable to use encrypted email, you may also report new issues at: 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/.) 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. The Knowledgebase article https://kb.isc.org/docs/cve-2022-0635 is the complete and official security advisory document. Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time. A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors. _____________________________________________________________________ CVE-2022-0667: Assertion failure on delayed DS lookup Updated on 16 Mar 2022 2 Minutes to read Contributors Greg ChoulesPeter Davies CVE: CVE-2022-0667 Document version: 2.0 Posting date: 16 March 2022 Program impacted: BIND Versions affected: BIND 9.18.0 Severity: High Exploitable: Remotely Description: In BIND 9.18.0 the recursive client code was refactored. This refactoring introduced a "backstop lifetime timer". While BIND is processing a request for a DS record that needs to be forwarded, it waits until this processing is complete or until the backstop lifetime timer has timed out. When the resume_dslookup() function is called as a result of such a timeout, the function does not test whether the fetch has previously been shut down. This introduces the possibility of triggering an assertion failure, which could cause the BIND process to terminate. Only the BIND 9.18 branch is affected. Impact: When the vulnerability is triggered the BIND process will exit. CVSS Score: 7.0 CVSS Vector: CVSS:3.1:AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:F/RL:O/RC:C 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/E:F/RL:O/RC:C. Workarounds: No workarounds known. Active exploits: We are not aware of any active exploits. Solution: Users of BIND 9.18.0 should upgrade to BIND 9.18.1 Document revision history: 1.0 Early Notification, 9 March 2022 2.0 Public disclosure, 16 March 2022 Related documents: See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected. Do you still have questions? Questions regarding this advisory should go to 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/. If you are unable to use encrypted email, you may also report new issues at: 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/.) 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. This Knowledgebase article https://kb.isc.org/docs/cve-2022-0667 is the complete and official security advisory document. Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time. A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors. ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23/25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email:cert@support.renater.fr + =========================================================