CVE-2020-8621— Attempting QNAME minimization after forwarding can lead to an assertion failure in resolver.c
Quick assessment
Affected
ISC BIND9
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
ISC BIND是美国ISC公司的一套实现了DNS协议的开源软件。 BIND 9.14.0至9.16.5, 9.17.0至9.17.3存在安全漏洞，攻击者可以构造一个特殊请求造成目标服务异常结束。
Possible ATT&CK Techniques 1 AI
T1203 · Exploitation for Client Execution
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I. Basic Information for CVE-2020-8621
Vulnerability Information
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Vulnerability Title
Attempting QNAME minimization after forwarding can lead to an assertion failure in resolver.c
Source: CVE Program / CVE List V5
Vulnerability Description
In BIND 9.14.0 -> 9.16.5, 9.17.0 -> 9.17.3, If a server is configured with both QNAME minimization and 'forward first' then an attacker who can send queries to it may be able to trigger the condition that will cause the server to crash. Servers that 'forward only' are not affected.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
ISC BIND 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
ISC BIND是美国ISC公司的一套实现了DNS协议的开源软件。 BIND 9.14.0至9.16.5, 9.17.0至9.17.3存在安全漏洞，攻击者可以构造一个特殊请求造成目标服务异常结束。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2020-8621
| # | POC Description | Source Link | Shenlong Link |
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Vendor Advisories for CVE-2020-8621 (3)
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https://security.netapp.com/advisory/ntap-20200827-0003/ x_refsource_CONFIRM
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Mailing List Discussions for CVE-2020-8621 (2)
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http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html vendor-advisory x_refsource_SUSE
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http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html vendor-advisory x_refsource_SUSE
Other References for CVE-2020-8621 (2)
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https://kb.isc.org/docs/cve-2020-8621 x_refsource_CONFIRM
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https://www.synology.com/security/advisory/Synology_SA_20_19 x_refsource_CONFIRM
Same Patch Batch · ISC · 2020-08-21 · 5 CVEs total
| CVE-2020-8620 | 7.5 HIGH | Internet Systems Consortium BIND server 安全漏洞 |
| CVE-2020-8623 | 7.5 HIGH | A flaw in native PKCS#11 code can lead to a remotely triggerable assertion failure in pk11 |
| CVE-2020-8622 | 6.5 MEDIUM | A truncated TSIG response can lead to an assertion failure |
| CVE-2020-8624 | 4.3 MEDIUM | update-policy rules of type "subdomain" are enforced incorrectly |
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V. Comments for CVE-2020-8621
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