CVE-2021-25218— A too-strict assertion check could be triggered when responses in BIND 9.16.19 and 9.17.16 require UDP fragmentation if RRL is in use
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。 ISC BIND 存在处理逻辑错误漏洞，该漏洞源于 named 尝试使用大于当前有效接口最大传输单元 (MTU) 的响应通过 UDP 进行响应，并且如果响应速率限制 (RRL) 处于活动状态，则会触发断言失败（导致 named 服务器进程终止）。
Possible ATT&CK Techniques 1 AI
T1499 · Endpoint Denial of Service
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I. Basic Information for CVE-2021-25218
Vulnerability Information
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Vulnerability Title
A too-strict assertion check could be triggered when responses in BIND 9.16.19 and 9.17.16 require UDP fragmentation if RRL is in use
Source: CVE Program / CVE List V5
Vulnerability Description
In BIND 9.16.19, 9.17.16. Also, version 9.16.19-S1 of BIND Supported Preview Edition When a vulnerable version of named receives a query under the circumstances described above, the named process will terminate due to a failed assertion check. The vulnerability affects only BIND 9 releases 9.16.19, 9.17.16, and release 9.16.19-S1 of the BIND Supported Preview Edition.
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 处理逻辑错误漏洞
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。 ISC BIND 存在处理逻辑错误漏洞，该漏洞源于 named 尝试使用大于当前有效接口最大传输单元 (MTU) 的响应通过 UDP 进行响应，并且如果响应速率限制 (RRL) 处于活动状态，则会触发断言失败（导致 named 服务器进程终止）。
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-2021-25218
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Vendor Advisories for CVE-2021-25218 (1)
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https://security.netapp.com/advisory/ntap-20210909-0002/ x_refsource_CONFIRM
Mailing List Discussions for CVE-2021-25218 (3)
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https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZPJCLGSR4BTGFLBLGIE5TEQP2SNJKGVL/ vendor-advisory x_refsource_FEDORA
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Other References for CVE-2021-25218 (1)
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https://kb.isc.org/v1/docs/cve-2021-25218 x_refsource_CONFIRM
IV. Related Vulnerabilities
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-
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Same vendor: ISC
-
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Cache poisoning possible with label count discrepancy, RRSIG -
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Potential memory usage beyond configured limits
V. Comments for CVE-2021-25218
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